Device for performing wireless communication

ABSTRACT

[Object] To enable a frequency band shared between wireless communication of a cellular system and wireless communication conforming to a wireless LAN standard to be more appropriately used in the cellular system. 
     [Solution] There is provided a device including an acquisition unit configured to acquire information indicating a terminal device which is a device candidate for performing wireless communication of a cellular system using a frequency band shared between the wireless communication of the cellular system and wireless communication conforming to a wireless local area network (LAN) standard, and a control unit configured to notify the terminal device that the terminal device is the device candidate.

TECHNICAL FIELD

The present disclosure relates to a device.

BACKGROUND ART

In the 3^(rd) Generation Partnership Project (3GPP), varioustechnologies for improving system throughput have been discussed. It maybe said that a first shortcut for improving the system throughput isincreasing a frequency to be used. In the 3GPP, the technology ofcarrier aggregation (CA) has been considered in Release 10 and Release11. CA is a technology for improving the system throughput and a maximumdata rate by aggregating component carriers (CCs) having a bandwidth of20 MHz for use. A frequency band available as a CC must adopt thetechnology of such CA. Thus, a frequency band available for wirelesscommunication of a cellular system is required.

For example, in Patent Literature 1, technology which enables aregistered frequency band available for a registered provider and anunlicensed band available when a predetermined condition is satisfied tobe used in addition to a dedicated frequency band allocated to eachprovider for exclusive use is disclosed.

CITATION LIST Patent Literature

Patent Literature 1: JP 2006-094001A

SUMMARY OF INVENTION Technical Problem

However, for example, even when a frequency band to be used in wirelesscommunication of a wireless local area network (LAN) is also used inwireless communication of a cellular system, the above-mentionedfrequency band is not likely to be appropriately used in wirelesscommunication of the above-mentioned cellular system.

An example in which the cellular system uses the above-mentionedfrequency band on the basis of carrier sense multiple access withcollision avoidance (CSMA/CA) is considered. However, because theCSMA/CA is a mechanism for simultaneously enabling only one-to-onecommunication, undesirable results can be caused when the CSMA/CA isapplied as is to a cellular system in which a frequency band is usedsimultaneously by one base station and a plurality of terminal devices.For example, the wireless communication of the cellular system isperformed in a state in which no hidden terminal problem is solved.

Therefore, it is desirable to provide a mechanism which enables afrequency band shared between wireless communication of a cellularsystem and wireless communication conforming to a wireless LAN standardto be more appropriately used in the cellular system.

Solution to Problem

According to the present disclosure, there is provided a deviceincluding: an acquisition unit configured to acquire informationindicating a terminal device which is a device candidate for performingwireless communication of a cellular system using a frequency bandshared between the wireless communication of the cellular system andwireless communication conforming to a wireless local area network (LAN)standard; and a control unit configured to notify the terminal devicethat the terminal device is the device candidate.

According to the present disclosure, there is provided a deviceincluding: a recognition unit configured to recognize that a terminaldevice is a device candidate for performing wireless communication of acellular system using a frequency band shared between the wirelesscommunication of the cellular system and wireless communicationconforming to a wireless local area network (LAN) standard through anotification by a base station of the cellular system; and a controlunit configured to perform control for using the frequency band in thewireless communication of the cellular system when the terminal deviceis the device candidate.

Advantageous Effects of Invention

According to the above-described present disclosure, a frequency bandshared between wireless communication of a cellular system and wirelesscommunication conforming to a wireless LAN standard can be moreappropriately used in the cellular system. Note that the effectsdescribed above are not necessarily limited, and along with or insteadof the effects, any effect that is desired to be introduced in thepresent specification or other effects that can be expected from thepresent specification may be exhibited.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory diagram illustrating a frame format ofInstitute of Electrical and Electronics Engineers (IEEE) 802.11.

FIG. 2 is an explanatory diagram illustrating a frame format oflong-term evolution (LTE).

FIG. 3 is an explanatory diagram illustrating an example of a schematicconfiguration of a cellular system according to an embodiment of thepresent disclosure.

FIG. 4 is an explanatory diagram illustrating an example of acommunication area of a wireless local area network (LAN) overlapping asmall cell.

FIG. 5 is an explanatory diagram illustrating an example of acommunication area of a wireless LAN overlapping a macro cell.

FIG. 6 is a block diagram illustrating an example of a configuration ofa base station according to the embodiment.

FIG. 7 is a block diagram illustrating a first example of aconfiguration of cellular communication according to the embodiment.

FIG. 8 is a block diagram illustrating a second example of aconfiguration of cellular communication according to the embodiment.

FIG. 9 is a block diagram illustrating a third example of aconfiguration of cellular communication according to the embodiment.

FIG. 10 is a block diagram illustrating a fourth example of aconfiguration of cellular communication according to the embodiment.

FIG. 11 is an explanatory diagram illustrating an example of cellularcommunication when time division duplex (TDD) is adopted.

FIG. 12 is an explanatory diagram illustrating an example of cellularcommunication when frequency division duplex (FDD) is adopted.

FIG. 13 is an explanatory diagram illustrating another example ofcellular communication when FDD is adopted.

FIG. 14 is a block diagram illustrating an example of a configuration ofa terminal device according to the embodiment.

FIG. 15 is a sequence diagram illustrating a first example of aschematic flow of a process according to the embodiment.

FIG. 16 is a sequence diagram illustrating a second example of aschematic flow of a process according to the embodiment.

FIG. 17 is a sequence diagram illustrating a third example of aschematic flow of a process according to the embodiment.

FIG. 18 is an explanatory diagram illustrating an example of acquisitionof synchronization for a shared band.

FIG. 19 is a flowchart illustrating an example of a schematic flow of aprocess according to a first modified example of the embodiment.

FIG. 20 is a sequence diagram illustrating an example of a schematicflow of a process according to a second modified example of theembodiment.

FIG. 21 is a block diagram illustrating a first example of a schematicconfiguration of an eNB.

FIG. 22 is a block diagram illustrating a second example of a schematicconfiguration of an eNB.

FIG. 23 is a block diagram illustrating an example of a schematicconfiguration of a smartphone.

FIG. 24 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device.

DESCRIPTION OF EMBODIMENT(S)

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail and with reference to the attached drawings. Notethat, in this specification and the appended drawings, structuralelements that have substantially the same function and structure aredenoted with the same reference numerals, and repeated explanation ofthese structural elements is omitted.

Also, the description will be given in the following order.

1. Introduction

2. Schematic configuration of system

3. Configuration of each device

-   -   3.1. Configuration of base station    -   3.2. Configuration of terminal device

4. Flow of process

5. First modified example

6. Second modified example

7. Application example

-   -   7.1. Application example related to base station    -   7.2. Application example related to terminal device

8. Conclusion

<<1. Introduction>>

First, sharing of a frequency band, technology of wireless communicationconforming to a wireless local area network (LAN) standard, andtechnology of wireless communication of a cellular system will bedescribed with reference to FIGS. 1 and 2.

(Sharing of Frequency Band)

A frequency band available for the wireless communication of thecellular system is required. For example, a band of 5 GHz is consideredas a frequency band for use in wireless communication of the cellularsystem (hereinafter referred to as “cellular communication”).

However, the band of 5 GHz is used in wireless communication conformingto the wireless LAN standard (hereinafter referred to as “wireless LANcommunication”). Thus, when the cellular system uses the band of 5 GHz,for example, the band of 5 GHz is shared between cellular communicationand wireless LAN communication. Specifically, for example, a frequencyband of 5GHz (for example, a channel of a wireless LAN) is used in thewireless LAN communication at a certain time and used in the cellularcommunication at another time. Thereby, frequency utilization efficiencyof the band of 5 GHz is improved. Also, the wireless LAN standardincludes Institute of Electrical and Electronics Engineers (IEEE)802.11a, 11b, 11g, 11n, 11ac, and 11ad, etc. and these standards arecharacterized in that IEEE 802.11 is adopted for a media access control(MAC) layer.

Devices for performing wireless LAN communication are already widespreadin the world. Thus, from the viewpoint of backward compatibility, amechanism for sharing a frequency band between cellular communicationand wireless LAN communication without changing an operation of thedevice for performing the wireless LAN communication is considered asthe technology of Long Term Evolution (LTE) and is desired to be definedas a new standard of LTE. Also, a terminal device conforming to theabove-mentioned new standard uses the shared frequency band, but aterminal device which does not conform to the above-mentioned newstandard is considered as a terminal device not using the sharedfrequency band.

In LTE, LTE-Advanced, or a cellular system conforming to a communicationstandard equivalent thereto, the shared frequency band will be used as,for example, a component carrier (CC). Further, it is assumed that thefrequency band of the cellular system is used as a primary componentcarrier (PCC) and the shared frequency band is used as a secondarycomponent carrier (SCC). Also, a control signal and a data signal can betransmitted and received using a frequency band of the cellular systemand the data signal can be transmitted and received using the sharedfrequency band.

(Technology of Wireless Communication Conforming to Wireless LANStandard)

A frame format of IEEE 802.11 will be described as the technology ofwireless communication conforming to the wireless LAN standard withreference to FIG. 1. FIG. 1 is an explanatory diagram illustrating aframe format of IEEE 802.11.

In IEEE 802.11, a DATA frame and an acknowledgement (ACK) frame arebasic frames. When the DATA frame is correctly received, the ACK frameis a frame which causes a transmitting side to know the success ofreception of the DATA frame. Although wireless LAN communication can beperformed only by the DATA frame and the ACK frame, two frames such as arequest to send (RTS) frame and a clear to send (CTS) frame aregenerally further used.

Before the RTS frame is transmitted, each terminal device which performsthe wireless LAN communication confirms that no signal is transmittedduring a period referred to as a distributed coordination function (DCF)inter-frame space (DIFS). This is referred to as carrier sense. Whenterminal devices simultaneously start to transmit signals at a point intime at which the DIFS has elapsed, the signals may collide with eachother. Thus, each terminal device waits for a backoff time randomly setfor each terminal device and transmits a signal if no signal istransmitted for the backoff time.

Basically, the terminal device cannot transmit the signal while anysignal is detected. However, because there is a hidden terminal problem,an RTS frame and a CTS frame including a duration field for setting avalue referred to as a network allocation vector (NAV) are added. TheNAV is set on the basis of a value included in the duration field. Theterminal device setting the NAV avoids transmitting a signal during aperiod of the NAV.

First, a first terminal device for transmitting the DATA frame transmitsthe RTS frame. Then, another terminal device located around the firstterminal device receives the RTS frame and acquires a value included inthe duration field in the RTS frame. The other terminal device sets, forexample, its own NAV to the above-mentioned acquired value and avoidstransmitting a signal during the period of the NAV. For example, theperiod of the NAV is a period from the end of the RTS frame to the endof the ACK frame.

Also, a second terminal device for receiving the DATA frame transmitsthe CTS frame after only a short inter-frame space (SIFS) from the endof the RTS frame according to the reception of the RTS frame. Then,another terminal device located around the above-mentioned secondterminal device receives the CTS frame and acquires a value included inthe duration field in the CTS frame. The other terminal device sets, forexample, its own NAV to the above-mentioned acquired value and avoidstransmitting a signal during the period of the NAV. The period of theNAV is a period from the end of the CTS frame to the end of the ACKframe. Thereby, for example, it is possible to prevent the otherterminal device (that is, a hidden terminal for the above-mentionedfirst terminal device) close to the above-mentioned second terminaldevice without being close to the above-mentioned first terminal devicefrom transmitting a signal during communication of the above-mentionedfirst terminal device and the above-mentioned second terminal device.

Also, the RTS frame includes a frame control field, a reception addressfield, a transmission address field, and a frame check sequence (FCS) inaddition to the duration field. Also, the CTS frame includes a framecontrol field, a reception address field, and an FCS in addition to theduration field.

Also, the DIFS and the SIFS in the standard of the IEEE 802.11 serieshave, for example, the following lengths.

TABLE 1 802.11b 802.11g 802.11a 802.11n 802.11ac SIFS 10 us 10 us 16 us16 us 16 us DIFS 50 us 28 us 34 us 34 us 34 us

(Technology of Wireless Communication of Cellular System)

(a) Frame Format

The frame format of LTE will be described with reference to FIG. 2. FIG.2 is an explanatory diagram illustrating the frame format of LTE.

First, a unit of time such as a radio frame is used in LTE. One radioframe is 10 ms. Each radio frame is identified by a system frame number(SFN) which is any one of 0 to 1023.

The radio frame includes 10 sub-frames identified by #0 to #9. Eachsub-frame is 1 ms. Further, each sub-frame includes two slots and eachslot includes, for example, seven orthogonal frequency divisionmultiplexing (OFDM) symbols. That is, each sub-frame includes 14 OFDMsymbols. Also, the frame format illustrated in FIG. 2 is a frame formatof a downlink and the frame format of an uplink includes a singlecarrier frequency division multiple access (SC-FDMA) symbol in place ofan OFDM symbol.

(b) Carrier Aggregation

Component Carriers

With carrier aggregation in Release 10, up to a maximum of five CCs areaggregated for use by user equipment (UE). Each CC is a band with amaximum width of 20 MHz. Carrier aggregation includes a case in whichsuccessive CCs in the frequency direction are used, and a case in whichseparated CCs in the frequency direction are used. With carrieraggregation, the CCs to be used may be set for each UE.

PCC and SCC

In carrier aggregation, one of the multiple CCs used by a UE is aspecial CC. This special CC is called the primary component carrier(PCC). Also, the remaining CCs among the multiple CCs are calledsecondary component carriers (SCCs). The PCC may be different dependingon the UE.

Since the PCC is the most important CC among the multiple CCs, it isdesirable for the PCC to be the CC with the most stable communicationquality. Note that in actual practice, which CC to treat as the PCCdepends on the implementation.

The SCC is added to the PCC. In addition, an existing SCC that has beenadded may also be removed. Note that changing an SCC is conducted byremoving an existing SCC and adding a new SCC.

PCC Determination Method and Changing Method

When a UE connection is initially established and the status of the UEgoes from Radio Resource Control (RRC) Idle to RRC Connected, the CCthat the UE used during the establishment of the connection becomes thePCC for that UE. More specifically, a connection is established througha connection establishment procedure. At this point, the status of theUE goes from RRC Idle to RRC Connected. Also, the CC used in theprocedure becomes the PCC for the above UE. Note that the aboveprocedure is a procedure initiated from the UE side.

Additionally, PCC changing is conducted by a handover betweenfrequencies. More specifically, if a handover is specified in aconnection reconfiguration procedure, a PCC handover is conducted, andthe PCC is changed. Note that the above procedure is a procedureinitiated from the network side.

Adding SCC

As discussed above, the SCC is added to the PCC. As a result, the SCC isassociated with the PCC. In other words, the SCC is subordinate to thePCC. SSC addition may be conducted through a connection reconfigurationprocedure. Note that this procedure is a procedure initiated from thenetwork side.

Removing SSC

As discussed above, an SCC may be removed. SSC removal may be conductedthrough a connection reconfiguration procedure. Specifically, a specificSCC specified in a message is removed. Note that the above procedure isa procedure initiated from the network side.

In addition, the removal of all SCCs may be conducted through aconnection re-establishment procedure.

Special Role of PCC

The connection establishment procedure, the transmitting and receivingof non-access stratum (NAS) signaling, and the transmitting andreceiving of uplink control signals on the physical uplink controlchannel (PUCCH) are conducted only by the PCC, and not by the SCCs.

In addition, the detection of a radio link failure (RLF) and asubsequent connection re-establishment procedure are also conducted onlyby the PCC, and not by the SCCs.

(Conditions of Backhauling for Carrier Aggregation)

For example, an ACK of a downlink signal on an SCC is transmitted by thePUCCH of the PCC. Since the ACK is used for the retransmission of databy the evolved Node B (eNB), a delay of the ACK is not acceptable.Consequently, when a first eNB using a CC that acts as the PCC for a UEis different from a second eNB using a CC that acts as an SCC for theUE, a backhaul delay of approximately 10 ms between the first eNB andthe second eNB is desirable.

<<2. Schematic Configuration of Cellular System>>

Next, a schematic configuration of a cellular system 1 according to anembodiment of the present disclosure will be described with reference toFIGS. 3 to 5. FIG. 3 is an explanatory diagram illustrating an exampleof the schematic configuration of the cellular system 1 according to theembodiment of the present disclosure. Referring to FIG. 3, the system 1includes a base station 100 and a terminal device 200. The cellularsystem 1 is, for example, LTE, LTE-Advanced, or a system conforming to acommunication standard equivalent thereto.

(Base Station 100)

The base station 100 performs wireless communication (cellularcommunication) of the cellular system 1. That is, the base station 100performs wireless communication with the terminal device 200. Forexample, the base station 100 performs wireless communication with theterminal device 200 located within a cell 10 which is a communicationarea of the base station 100. Specifically, for example, the basestation 100 transmits a downlink signal to the terminal device 200 andreceives an uplink signal from the terminal device 200.

As an example, the base station 100 is a small base station and the cell10 is a small cell. As another example, the base station 100 may be amacro base station and the cell 10 may be a macro cell.

(Terminal Device 200)

The terminal device 200 performs wireless communication (cellularcommunication) of the cellular system.

For example, the terminal device 200 performs wireless communicationwith the base station 100. For example, when the terminal device 200 islocated within the cell 10 of the base station 100, the terminal device200 performs wireless communication with the base station 100.Specifically, for example, the terminal device 200 receives the downlinksignal from the base station 100 and transmits the uplink signal to thebase station 100.

Also, the terminal device 200 can perform wireless communication withanother terminal device (for example, another terminal device 200 or thelike). For example, the terminal device 200 can perform device-to-device(D2D) communication. Also, the terminal device 200 can perform wirelesscommunication within a localized network (LN) formed by the terminaldevice.

Also, the terminal device 200 may perform other wireless communication.For example, the terminal device 200 may perform wireless communication(wireless LAN communication) conforming to the wireless LAN standard.

(Frequency Band to be Used)

In wireless communication (that is, cellular communication) of thecellular system 1, the frequency band of the cellular system 1(hereinafter referred to as a “cellular band”) is used. The cellularband is, for example, a band allocated to a provider of the cellularsystem 1, and can be referred to as a licensed band.

Particularly, in the embodiment of the present disclosure, a frequencyband to be used in wireless communication (that is, wireless LANcommunication) conforming to a wireless LAN standard is also used incellular communication. That is, a frequency band shared between thecellular communication and the wire LAN communication (hereinafterreferred to as a “shared band”). The above-mentioned shared band is, forexample, a channel of a wireless LAN. As an example, the shared band isthe channel of 20 MHz.

(Wireless LAN)

A communication area of the wireless LAN can be located within the cell10. That is, the cell 10 can overlap the communication area of thewireless LAN. Hereinafter, in this regard, a specific example will bedescribed with reference to FIGS. 4 and 5.

FIG. 4 is an explanatory diagram illustrating an example of acommunication area of a wireless LAN overlapping a small cell. Referringto FIG. 4, the base station 100 which is a small base station and theterminal device 200 are illustrated. Further, an access point 30 of awireless LAN and a terminal device 50 for performing wireless LANcommunication are located around the base station 100 and the terminaldevice 200. A communication area 40 of the access point 30 overlaps thecell 10 which is a small cell.

FIG. 5 is an explanatory diagram illustrating an example of acommunication area of a wireless LAN overlapping a macro cell. Referringto FIG. 5, the base station 100 which is a macro base station and theterminal device 200 are illustrated. Further, the access point 30 of awireless LAN and the terminal device 50 for performing wireless LANcommunication are located around the base station 100 and the terminaldevice 200. The communication area 40 of the access point 30 overlapsthe cell 10 which is a macro cell.

Also, the wireless LAN communication (that is, the wirelesscommunication conforming to the wireless LAN standard) can includewireless communication conforming to a wireless LAN standard betweenterminal devices which perform the wireless LAN communication inaddition to wireless communication between the wireless LAN access pointand the terminal device (which perform wireless LAN communication). Asan example, the wireless LAN communication can also include wirelesscommunication according to Wi-Fi Direct.

The cellular system 1 according to the embodiment of the presentdisclosure has been described above. Also, the cellular system 1 caninclude a plurality of base stations 100 as well as one base station100. Also, the cellular system 1 can include another device in additionto the base station 100 and the terminal device 200. For example, thecellular system 1 can include core network nodes (for example, amobility management entity (MME), a serving gateway (S-GW), and a packetdata network gateway (P-GW), etc.).

<<3. Configuration of Each Device>>

Next, a configuration of each device according to the present embodimentwill be described with reference to FIGS. 6 to 14.

<3.1. Configuration of Base Station>

Next, an example of the configuration of a base station 100-1 accordingto the first embodiment will be described with reference to FIGS. 6 to10. FIG. 6 is a block diagram illustrating an example of theconfiguration of the base station 100-1 according to the firstembodiment. Referring to FIG. 6, the base station 100-1 is equipped withan antenna unit 110, a wireless communication unit 120, a networkcommunication unit 130, a storage unit 140, and a processing unit 150.

(Antenna Unit 110)

The antenna unit 110 emits a signal output by the wireless communicationunit 120 into space as a radio wave. Additionally, the antenna unit 110converts a radio wave from space into a signal, and outputs the signalto the wireless communication unit 120.

(Wireless Communication Unit 120)

The wireless communication unit 120 transmits and receives signals. Forexample, the wireless communication unit 120 transmits a downlink signalto a terminal device 200 positioned within the cell 10, and receives anuplink signal from the terminal device 200 positioned within the cell10.

For example, the wireless communication unit 120 transmits and receivesa signal using the frequency band of the cellular system 1 (that is, acellular band). Also, particularly, in the embodiment of the presentdisclosure, the wireless communication unit 120 transmits and receives asignal using the frequency band shared between the cellularcommunication and the other wireless communication (for example,wireless LAN communication) (that is, a shared band).

(Network Communication Unit 130)

The network communication unit 130 communicates with other nodes. Forexample, the network communication unit 130 communicates with corenetwork nodes (for example, MME, S-GA, P-GW, etc.). Also, the networkcommunication unit 130 communicates with another base station 100.

(Storage Unit 140)

The storage unit 140 temporarily or permanently stores programs and datafor the operation of the base station 100.

(Processing Unit 150)

The processing unit 150 provides various functions of the base station100. The processing unit 150 includes an information acquisition unit151 and a communication control unit 153. Also, the processing unit 150can further include another constituent element other than theseconstituent elements.

(Information Acquisition Unit 151)

The information acquisition unit 151 acquires information indicating theterminal device 200 which is a device candidate for performing cellularcommunication (hereinafter, “device candidate information”) using afrequency band shared between the cellular communication and thewireless LAN communication (that is, a shared band).

For example, the processing unit 150 (for example, the informationacquisition unit 151, the communication control unit 153, or anotherconstituent element) determines a device candidate for performingcellular communication using the above-mentioned shared band from amonga plurality of terminal devices 200 communicable with the base station100. Information indicating the terminal device 200 which is the devicecandidate (that is, device candidate information) is stored in thestorage unit 140. Thereafter, the information acquisition unit 151acquires the above-mentioned device candidate information at any timing.

As an example, the above-mentioned device candidate information is alist including identification information of each terminal device 200which is the above-mentioned device candidate.

(Communication Control Unit 153)

(a) Notification of Device Candidate

The communication control unit 153 notifies the terminal device 200 thatthe terminal device 200 is the above-mention device candidate.

Timing of Notification

For example, the communication control unit 153 notifies the terminaldevice 200 that the terminal device 200 is the above-mentioned devicecandidate before the above-mentioned shared band is used in the cellularcommunication. Thereby, for example, the communication control unit 153can cause the terminal device 200 which is the above-mentioned candidateto perform a preparatory operation for using the above-mentioned sharedband in cellular communication.

Frequency Band to be Used

For example, the communication control unit 153 notifies the terminaldevice 200 that the terminal device 200 is the above-mentioned devicecandidate using the cellular band.

Specifically, for example, the communication control unit 153 notifiesthe above-mentioned terminal device 200 that the above-mentionedterminal device 200 is the above-mentioned device candidate using acellular band to be used in cellular communication by the base station100 and the terminal device 200 (for example, a CC).

Technique of Notification

For example, the communication control unit 153 notifies the terminaldevice 200 which is the above-mentioned device candidate that theterminal device 200 is the above-mentioned device candidate on the basisof device candidate information acquired by the information acquisitionunit 151. More specifically, for example, the communication control unit153 notifies the terminal device 200 for which identificationinformation is included in the above-mentioned device candidateinformation that the terminal device 200 is the above-mentioned devicecandidate.

First Example Notification in System Information Block (SIB)

As an example, the communication control unit 153 notifies the terminaldevice that the terminal device 200 is the above-mentioned devicecandidate in the SIB.

For example, the above-mentioned SIB includes the above-mentioned devicecandidate information. As described above, as an example, the devicecandidate information is a list including identification information ofeach terminal device 200 which is the above-mentioned device candidate.Through control by the communication control unit 153, the base station100 transmits the SIB including the above-described device candidateinformation. For example, the communication control unit 153 generatesthe above-mentioned SIB. Also, for example, the communication controlunit 153 allocates radio resources including the above-mentioned devicecandidate information to the above-mentioned SIB.

Thereby, for example, a notification of a large number of terminaldevices 200 by less radio resources is possible.

Second Example Notification by Signaling

As another example, the communication control unit 153 may notify theterminal device 200 that the terminal device 200 is the above-mentioneddevice candidate by individual signaling for the terminal device 200.

For example, the above-mentioned individual signaling may be radioresource control (RRC) signaling. Through control by the communicationcontrol unit 153, the base station 100 may transmit a message indicatingthat the terminal device 200 is the above-described device candidate bythe RRC signaling for the terminal device 200 which is theabove-mentioned device candidate. For example, the communication controlunit 153 may generate the message. Also, for example, the communicationcontrol unit 153 may allocate radio resources to the message.

Thereby, for example, a fast notification of the terminal device 200which is the above-mentioned device candidate is possible.

As mentioned above, the communication control unit 153 notifies theterminal device 200 that the terminal device 200 is the above-mentioneddevice candidate. Thereby, for example, the above-mentioned shared bandcan be more appropriately used in the cellular system 1. Specifically,for example, it is possible to cause the terminal device 200 which isthe above-mentioned device candidate to perform an operation for usingthe above-mentioned shared band in cellular communication. Also, becauseit is unnecessary for a terminal device 200 which is not theabove-described device candidate to perform any special operation, it ispossible to suppress an increase in the number of operations of theterminal device 200 which is not the above-described device candidate.

(b) Determination of Use of Shared Band

For example, the communication control unit 153 determines whether touse the above-mentioned shared band in the cellular communication beforethe base station 100 uses the above-mentioned shared band in thecellular communication.

For example, the communication control unit 153 determines whether touse the above-mentioned shared band in the cellular communication on thebasis of a result of carrier sensing for the above-mentioned shared bandby the terminal device 200 which is the above-mentioned devicecandidate.

Specifically, for example, one or more terminal devices 200 which arethe above-mentioned device candidates perform carrier sensing for theabove-mentioned shared band and provide results of the carrier sensingto the base station 100. The communication control unit 153 determineswhether to use the above-mentioned shared band in cellular communicationon the basis of the results of the above-mentioned carrier sensing bythe above-mentioned one or more terminal devices 200. As an example, thecommunication control unit 153 determines to use the above-mentionedshared band in the cellular communication when results of carriersensing of a predetermined number of terminal devices 200 or terminaldevices 200 of a predetermined ratio among the above-mentioned one ormore terminal devices 200 indicate that no signal is transmitted usingthe above-mentioned shared band. As another example, when all theresults of the carrier sensing of the above-mentioned one or moreterminal devices 200 indicate that no signal is transmitted using theabove-mentioned shared band, the communication control unit 153 maydetermine to use the above-mentioned shared band in the cellularcommunication.

Thereby, for example, when the above-mentioned shared band for thecellular communication is used, a usage state of the above-mentionedshared band in the periphery of the terminal device 200 is considered.Thus, the occurrence of interference between cellular communication bythe terminal device 200 and wireless LAN communication is suppressed.

(c) Transmission of Frame

For example, the communication control unit 153 controls thetransmission of the frame by the base station 100 so that the frameincluding duration information for setting an NAV is transmitted usingthe above-mentioned shared band before the above-mentioned shared bandis used in the cellular communication.

Thereby, for example, it is possible to cause the terminal device forperforming wireless LAN communication (hereinafter, referred to as a“wireless LAN device”) in which the above-mentioned frame is received toset the above-mentioned NAV. That is, it is possible to cause thewireless LAN device positioned in the periphery of the base station 100to set the above-mentioned NAV. Consequently, when the cellularcommunication is performed using the above-mentioned shared band, theuse of the above-mentioned shared band by the wireless LAN devicepositioned in the periphery of the base station 100 can be prevented.

Frame

For example, the above-mentioned frame has a duration field and includesthe above-mentioned duration information in the duration field.

As an example, the above-mentioned frame is an RTS frame. As anotherexample, the above-mentioned frame may be a CTS frame. As still anotherexample, the above-mentioned frame may be another type of frame similarto the RTS frame and the CTS frame.

Duration Information

As described above, the above-mentioned duration information isinformation for setting the NAV. For example, the above-mentionedduration information indicates the duration. Also, the duration is aperiod after the transmission of the above-mentioned frame and covers aperiod in which the cellular communication is performed using theabove-mentioned shared band. For example, the duration is determined bythe communication control unit 153.

According to the transmission of the frame including such durationinformation, for example, it is possible to cause the wireless LANdevice (that is, the wireless LAN device positioned in the periphery ofthe base station 100) for receiving the frame to set the NAV forcovering a period in which the cellular communication is performed usingthe above-mentioned shared band. Consequently, the use of theabove-mentioned shared band by the wireless LAN device positioned in theperiphery of the base station 100 can be prevented during the period inwhich the cellular communication is performed using the above-mentionedshared band.

Also, the duration indicated by the above-mentioned duration informationmay cover a part of the period in which the cellular communication isperformed using the above-mentioned shared band. An additional frameincluding the duration information for setting the NAV may betransmitted through control by the communication control unit 153 at anytiming after the transmission of the above-described frame. Also,another additional frame may be transmitted at any timing after thetransmission of the additional frame. One or more additional frames maybe transmitted at different timings as described above through controlby the communication control unit 153. Every time an additional frame istransmitted, the wireless LAN device can receive the additional frameand update the NAV on the basis of duration information included in theadditional frame. As a result, the above-mentioned time in which thecellular communication is performed using the above-mentioned sharedband can be covered according to the duration information included inthe above-mentioned frame and the above-mentioned one or more additionalframes. Also, according to this technique, for example, it is possibleto further lengthen a period in which the above-mentioned shared band isused in the cellular communication.

Timing of Transmission

The above-mentioned frame is transmitted, for example, at a timing atwhich a period in which no signal is transmitted using theabove-mentioned shared band becomes a sum of a DIFS and a backoff time.For example, the communication control unit 153 controls theabove-mentioned frame to start to be transmitted as described above.

Also, the above-mentioned frame may start to be transmitted before theperiod in which no signal is transmitted using the above-mentionedshared band becomes the DIFS. Thereby, for example, it is possible tomore reliably transmit the above-mentioned frame using theabove-mentioned shared band. Further, the above-mentioned frame maystart to be transmitted after the period in which no signal istransmitted using the above-mentioned shared band is longer than theSIFS (and before the period becomes the DIFS). Thereby, for example, acollision of a signal of the above-mentioned frame with a signal ofwireless LAN communication can be avoided.

Specific Content of Control

For example, the processing unit 150 (the communication control unit 153or another constituent element) performs carrier sensing for theabove-mentioned shared band. When the period in which no signal istransmitted using the above-mentioned shared band becomes a sum of theDIFD and the backoff time, the communication control unit 153 triggersthe transmission of a frame including duration information for settingthe NAV. Then, the processing unit 150 (the communication control unit153 or another constituent element) generates a frame including durationinformation for setting the NAV. Also, for example, the processing unit150 (the communication control unit 153 or another constituent element)generates a signal of a physical layer of the above-mentioned frame byscrambling, encoding, interleaving, symbol mapping, modulation, etc. andcauses the wireless communication unit 120 to transmit the signal.

(d) Instruction of Transmission of Frame

For example, the communication control unit 153 instructs the terminaldevice 200 which is the above-described device candidate to transmit aframe including duration information for setting the NAV using theabove-mentioned shared band before the above-mentioned shared band isused in the cellular communication.

Thereby, for example, it is possible to cause the terminal device 200which is the above-mentioned device candidate to transmit theabove-mentioned frame before the cellular communication is performedusing the above-mentioned shared band. As a result, the wireless LANdevice for receiving the above-described frame can set theabove-mentioned NAV. That is, it is possible to cause the wireless LANdevice positioned in the periphery of the terminal device 200 which isthe above-mentioned device candidate to set the above-mentioned NAV.Consequently, when the cellular communication is performed using theabove-mentioned shared band, the use of the above-mentioned shared bandby the wireless LAN device positioned in the periphery of theabove-mentioned terminal device 200 can be prevented. That is, a hiddenterminal problem can be solved.

Frame

For example, the above-mentioned frame has a duration field and includesthe above-mentioned duration information in the duration field.

As an example, the above-mentioned frame is a CTS frame. As anotherexample, the above-mentioned frame may be an RTS frame. As still anotherexample, the above-mentioned frame may be another type of frame similarto the RTS frame and the CTS frame.

Technique of Instruction

First Example Instruction Using Cellular Band

As the first example, the communication control unit 153 uses a cellularband to instruct the above-mentioned terminal device 200 to transmit theabove-mentioned frame using the above-mentioned shared band.

For example, using the cellular band used in the cellular communicationby the base station 100 and the terminal device 200 (for example, a CC),the communication control unit 153 instructs the above-mentionedterminal device 200 to transmit the above-mentioned frame using theabove-mentioned shared band.

As an example, the communication control unit 153 instructs theabove-mentioned terminal device 200 to transmit the above-mentionedframe using the above-mentioned shared band by individual signaling forthe above-mentioned terminal device 200 which is the above-mentioneddevice candidate. For example, through control by the communicationcontrol unit 153, the base station 100 transmits a frame transmissioninstruction message for performing an instruction for the transmissionof the above-mentioned frame using the above-mentioned shared band byRRC signaling for the terminal device 200 which is the above-mentioneddevice candidate. For example, the communication control unit 153generates the message. Also, for example, the communication control unit153 allocates radio resources to the message.

By performing the instruction using the cellular band, for example, theterminal device 200 can transmit a frame such as a CTS frame withoutdecrypting the RTS frame. That is, a burden on the terminal device 200can be reduced. Also, by individual signaling for the terminal device200, for example, a fast notification of the terminal device 200 whichis the above-mentioned device candidate is possible.

Also, the communication control unit 153 instructs the above-mentionedterminal device 200 to transmit the above-mentioned frame using theabove-mentioned shared band, for example, after the base station 100transmits a frame including duration information for setting the NAV(for example, an RTS frame).

Also, the communication control unit 153 may instruct theabove-mentioned terminal device 200 to transmit the above-mentionedframe using the above-mentioned shared band in an SIB in place ofindividual signaling.

Provision of Timing Information

For example, the communication control unit 153 provides theabove-mentioned terminal device 200 with information which specifies thetiming at which the above-mentioned frame is transmitted (hereinafterreferred to as “timing information).

Specifically, for example, through control by the communication controlunit 153, the base station 100 transmits a frame transmissioninstruction message including the above-mentioned timing information tothe terminal device 200 using the cellular band.

For example, the above-described timing is any timing after the basestation 100 transmits a frame including duration information for settingthe NAV (for example, an RTS frame).

According to provision of the above-mentioned timing information, forexample, the base station 100 can control the timing of frametransmission by the terminal device 200. Also, according to theprovision of the above-mentioned timing information, for example, it ispossible to cause a plurality of terminal devices 200 to simultaneouslytransmit frames.

Provision of Duration Information

Also, for example, the communication control unit 153 provides theterminal device 200 with the above-mentioned duration informationincluded in the above-mentioned frame. Alternatively, the communicationcontrol unit 153 provides the above-mentioned terminal device 200 withinformation which specifies the duration information.

Specifically, for example, through control by the communication controlunit 153, the base station 100 transmits a fame transmission instructionmessage including the above-mentioned duration information (orinformation which specifies the above-mentioned duration information)included in the above-mentioned frame using the cellular band to theterminal device 200.

For example, the duration indicated by the above-mentioned durationinformation is a duration from a point in time at which an SIFS haselapsed from an end time-point of transmission of the above-mentionedframe transmitted by the terminal device 200 to a point in time at whichthe duration indicated by the duration information included in the frametransmitted by the base station 100 ends.

According to provision of the above-mentioned duration information, forexample, the base station 100 can control a period in which the wirelessLAN device for receiving a frame transmitted by the terminal device 200avoids transmitting a signal.

Second Example Instruction by Other Frame for Triggering Transmission ofFrame

As the second example, the communication control unit 153 may instructthe above-mentioned terminal device 200 to transmit the above-mentionedframe using the above-mentioned shared band by another frame fortriggering the transmission of the above-mentioned frame by theabove-mentioned terminal device 200.

As described above, for example, the communication control unit 153controls the transmission of the frame so that a frame includingduration information for setting the NAV is transmitted using theabove-mentioned shared band (by the base station 100). For example, theframe is the above-mentioned other frame (that is, another frame fortriggering the transmission of the above-mentioned frame by theabove-described terminal device 200).

For example, the above-mentioned frame has a reception address field andincludes a predetermined value in the reception address field. Theterminal device 200 which is the above-mentioned device candidatetransmits a frame including duration information for setting the NAVusing the above-mentioned shared band when the above-mentioned otherframe including the above-mentioned predetermined value in the receptionaddress field is received using the above-mentioned shared band. Also, apredetermined value may be included in another field (for example, atransmission address field) in place of the reception address field, andthe terminal device 200 may transmit the above-described other frameusing the above-mentioned shared band when the frame including theabove-mentioned value is received using the above-mentioned shared band.

As an example, the above-mentioned other frame is an RTS frame andtriggers the transmission of a CTS frame by the terminal device 200which is the above-mentioned device candidate.

According to the instruction by the above-mentioned other frame, forexample, it is possible to cause the above-mentioned terminal device 200which is the above-mentioned device candidate to more quickly transmitthe above-mentioned frame.

(e) Cellular Communication

For example, the communication control unit 153 controls wirelesscommunication (that is, the cellular communication) of the cellularsystem 1.

For example, the communication control unit 153 controls wirelesscommunication using the above-mentioned shared band. Also, for example,the communication control unit 153 controls wireless communication usinga cellular band.

Example of Cellular Communication Using Shared Band

Hereinafter, an example of cellular communication using theabove-mentioned shared band will be described with reference to FIGS. 7to 13.

First Example

FIG. 7 is an explanatory diagram illustrating the first example of thecellular communication according to an embodiment of the presentdisclosure. Referring to FIG. 7, first, the base station 100 transmitsan RTS frame using the shared band. Also, the base station 100 transmitsa frame transmission instruction message including timing informationand duration information to the terminal device 200 using the cellularband. The terminal device 200 transmits a CTS frame including theabove-mentioned duration information using the above-mentioned sharedband at a timing indicated by the above-mentioned timing information. Ata point in time at which an SIFS has elapsed from an end time-point ofthe transmission (or the reception) of the CTS frame, the base station100 starts the cellular communication with the terminal device 200 usingthe above-mentioned shared band. Also, the base station 100 ends thecellular communication before the passage of the period of an NAV setaccording to the RTS frame (or a period of the NAV set according to theCTS frame).

Second Example

FIG. 8 is an explanatory diagram illustrating the second example ofcellular communication according to an embodiment of the presentdisclosure. Referring to FIG. 8, first, the base station 100 transmitsan RTS frame using a shared band. Then, the terminal device 200transmits a CTS frame using the above-mentioned shared band according tothe reception of the RTS frame. At a point in time at which the SIFS haselapsed from an end time-point of the transmission (or the reception) ofthe CTS frame, the base station 100 starts cellular communication withthe terminal device 200 using the above-mentioned shared band. Also, thebase station 100 ends the cellular communication before the passage ofthe period of an NAV set according to the RTS frame (or the period ofthe NAV set according to the CTS frame).

Third Example

FIG. 9 is an explanatory diagram illustrating the third example ofcellular communication according to an embodiment of the presentdisclosure. Referring to FIG. 9, the base station 100 transmits a frametransmission instruction message including timing information andduration information to the terminal device 200 using a cellular band,and the terminal device 200 transmits a CTS frame including theabove-mentioned duration information using the above-mentioned sharedband at a timing indicated by the timing information. At a point in timeat which the SIFS has elapsed from the end time-point of thetransmission (or the reception) of the CTS frame, the base station 100starts the cellular communication with the terminal device 200 using theabove-mentioned shared band. Also, the base station 100 ends thecellular communication before the passage of the period of an NAV setaccording to the CTS frame.

Fourth Example

FIG. 10 is an explanatory diagram illustrating the fourth example ofcellular communication according to an embodiment of the presentdisclosure. Referring to FIG. 10, the base station 100 transmits an RTSframe using a shared band. At a point in time at which the SIFS haselapsed from an end time-point of the transmission (or the reception) ofthe RTS frame, the base station 100 starts cellular communication withthe terminal device 200 using the above-mentioned shared band. Also, thebase station 100 ends the cellular communication before the passage ofthe period of an NAV set according to the RTS frame.

Duplex Operation

In the cellular system 1, time division duplex (TDD) or frequencydivision duplex (FDD) are adopted as the duplex operation. That is, theduplex operation of the cellular system 1 is the TDD or FDD.

TDD

As the first example, the TDD is adopted as the duplex operation in thecellular system 1. That is, the duplex operation of the cellular system1 is the TDD. In this case, the above-mentioned shared band is used as aband for both downlink and uplink in the cellular system 1. Hereinafter,an example of the cellular communication when the TDD is adopted will bedescribed with reference to FIG. 11.

FIG. 11 is an explanatory diagram illustrating an example of cellularcommunication when the TDD is adopted. Referring to FIG. 11, forexample, within a period in which the cellular communication isperformed using a shared band, the base station 100 transmits a signalto the terminal device 200 using the shared band in a downlink frame,and the terminal device 200 receives the signal. Also, in an uplinksub-frame within the above-mentioned period, the terminal device 200transmits a signal to the base station 100 using the above-mentionedshared band, and the base station 100 receives the signal.

Also, cellular communication of only one radio frame is illustrated inthe example of FIG. 11, but, of course, cellular communication of two ormore frames may be performed. This is applied to FIGS. 12 and 13 whichwill be described below as well as FIG. 11.

FDD

As the second example, the FDD is adopted as the duplex operation in thecellular system 1. That is, the duplex operation of the cellular system1 is the FDD.

For example, a partial band included in the above-mentioned shared bandin the cellular system 1 is used as a downlink band and another partialband included in the above-mentioned shared band is used as an uplinkband. Hereinafter, an example of cellular communication when the FDD isadopted will be described with reference to FIG. 12.

FIG. 12 is an explanatory diagram illustrating an example of cellularcommunication when the FDD is adopted. Referring to FIG. 12, forexample, within a period in which the cellular communication isperformed using a shared band, the base station 100 transmits a signalto the terminal device 200 using a partial band of the shared band as adownlink band, and the terminal device 200 receives the signal. Also,within the above-mentioned period, the terminal device 200 transmits asignal to the base station 100 using another partial band of theabove-mentioned shared band as an uplink band, and the base station 100receives the signal.

Also, two shared bands may be used in place of using the partial band ofthe shared band as the downlink band and using the other partial band ofthe shared band as the uplink band. In this case, in the cellular system1, one of the two shared bands may be used as the downlink band and theother of the two shared bands may be used as the uplink band.

Also, the shared band may be used as one of the downlink band and theuplink band. For example, the shared band may be used as the downlinkband in the cellular system 1. The cellular band may be used as theuplink band corresponding to the above-mentioned shared band. That is,an uplink control signal associated with the shared band may betransmitted to the base station 100 by the terminal device 200 using thecellular band. Hereinafter, in this regard, a specific example will bedescribed with reference to FIG. 13.

FIG. 13 is an explanatory diagram illustrating another example ofcellular communication when the FDD is adopted. Referring to FIG. 13,within a period in which the cellular communication is performed usingthe shared band, the base station 100 may transmit a signal to theterminal device 200 using the shared band as a downlink band, and theterminal device 200 may receive the signal. Also, an uplink controlsignal associated with the shared band may be transmitted to the basestation 100 by the terminal device 200 using the cellular band.

By using the shared band as the downlink band, for example, a hiddenterminal problem can be reduced. Specifically, for example, because theterminal device 200 does not transmit an uplink signal using theabove-mentioned shared band, the interference to wireless LANcommunication of the wireless LAN device positioned in the periphery ofthe terminal device 200 is suppressed.

<3.2. Configuration of Terminal Device>

Next, an example of a configuration of the terminal device 200-1according to an embodiment of the present disclosure will be describedwith reference to FIG. 14. FIG. 14 is a block diagram illustrating theexample of the configuration of the terminal device 200 according to anembodiment of the present disclosure. Referring to FIG. 14, the terminaldevice 200 includes an antenna unit 210, a wireless communication unit220, a storage unit 230, and a processing unit 240.

(Antenna Unit 210)

The antenna unit 210 emits a signal output by the wireless communicationunit 220 into space as a radio wave. Additionally, the antenna unit 210converts a radio wave from space into a signal, and outputs the signalto the wireless communication unit 220.

(Wireless Communication Unit 220)

The wireless communication unit 220 transmits and receives a signal. Forexample, the wireless communication unit 220 receives a downlink signalfrom the base station 100 and transmits an uplink signal to the basestation 100 when the terminal device 200 is located within the cell 10.

For example, the wireless communication unit 220 transmits and receivesa signal using a cellular band. Also, particularly, in the embodiment ofthe present disclosure, the wireless communication unit 220 transmitsand receives a signal using a frequency band shared between cellularcommunication and other wireless communication (for example, wirelessLAN communication) (that is, a shared band).

(Storage Unit 230)

The storage unit 230 temporarily or permanently stores programs and datafor the operation of the terminal device 200.

(Processing Unit 240)

The processing unit 240 provides various functions of the terminaldevice 200. The processing unit 240 includes a recognition unit 241 anda communication control unit 243. Also, the processing unit 240 canfurther include another constituent element other than these constituentelements.

(Recognition Unit 241)

The recognition unit 241 recognizes that the terminal device 200 is adevice candidate for performing cellular communication using the sharedband shared between the cellular communication and the wireless LANcommunication through a notification by the base station 100.

For example, when the terminal device 200 is a device candidate forperforming the cellular communication using the above-mentioned sharedband, the base station 100 (the communication control unit 153) notifiesthe terminal device 200 that the terminal device 200 is theabove-mentioned device candidate as described above. Thus, therecognition unit 241 recognizes that the terminal device 200 is theabove-mentioned device candidate according to the notification by thebase station 100.

(Communication Control Unit 243)

The communication control unit 243 performs control for using theabove-mentioned shared band in the cellular communication when theterminal device 200 is the above-mentioned device candidate.

(a) Report of Result of Carrier Sensing

For example, the above-mentioned control for using the above-mentionedshared band in the cellular communication includes reporting the resultof carrier sensing by the terminal device 200 to the base station 100.That is, the communication control unit 243 reports the result of thecarrier sensing by the terminal device 200 to the base station 100 whenthe terminal device 200 is the above-mentioned device candidate.

Specifically, for example, when the recognition unit 241 recognizes thatthe terminal device 200 is the above-mentioned device candidate, theprocessing unit 240 (the communication control unit 243 or anotherconstituent element) performs the carrier sensing for theabove-mentioned shared band. That is, the processing unit 240 confirmswhether a signal is transmitted using the above-mentioned shared band.The communication control unit 243 reports the result of theabove-mentioned carrier sensing to the base station 100 using thecellular band. As an example, the above-mentioned result of theabove-mentioned carrier sensing is information indicating whether thesignal is transmitted using the above-mentioned shared band.

According to the report of the result of the carrier sensing describedabove, for example, the base station 100 can know a usage state of theabove-mentioned shared band in the periphery of the terminal device 200.Thus, when the above-mentioned shared band for the cellularcommunication is used, the usage state of the above-mentioned sharedband in the periphery of the terminal device 200 is considered. Thus,the occurrence of interference between the cellular communication andthe wireless LAN communication by the terminal device 200 can besuppressed.

(b) Transmission of Frame

For example, the above-mentioned control for using the above-mentionedband in the cellular communication includes controlling the transmissionof the frame by the terminal device 200 so that the frame including theduration information for setting the NAV is transmitted using theabove-mentioned shared band. That is, the communication control unit 243controls the transmission of the frame by the terminal device 200 sothat the frame including the duration information for setting the NAV istransmitted using the above-mentioned shared band.

Frame

For example, the above-mentioned frame has a duration field and includesthe above-mentioned duration information in the duration field.

As an example, the above-mentioned frame is a CTS frame. As anotherexample, the above-mentioned frame may be an RTS frame. As still anotherexample, the above-mentioned frame may be another type of frame similarto the RTS frame and the CTS frame.

Transmission According to Instruction by Base Station

For example, the communication control unit 243 controls thetransmission of the frame by the terminal device 200 so that theabove-mentioned frame is transmitted using the above-mentioned sharedband according to the instruction by the base station 100.

First Example Instruction Using Cellular Band

As the first example, using the cellular band, the base station 100instructs the terminal device 200 to transmit the above-mentioned frameusing the above-mentioned shared band. According to this instruction,the communication control unit 243 controls the transmission of theframe by the terminal device 200 so that the above-mentioned frame istransmitted using the above-mentioned shared band.

For example, timing information which specifies a timing at which theabove-mentioned frame is transmitted is provided to the terminal device200 by the base station 100. The communication control unit 243 controlsthe transmission of the above-mentioned frame by the terminal device 200so that the above-mentioned frame (for example, the CTS frame) istransmitted at the timing specified from the timing information.

Also, for example, the duration information (or information whichspecifies the duration information) included in the above-mentionedframe is provided to the terminal device 200 by the base station 100.The communication control unit 243 controls the transmission of theabove-mentioned frame by the terminal device 200 so that the frame (forexample, the CTS frame) including the above-mentioned durationinformation provided by the base station 100 is transmitted.

Second Example Instruction by Other Frame for Triggering Transmission ofFrame

As the second example, the base station 100 instructs the terminaldevice 200 to transmit the above-mentioned frame using theabove-mentioned shared band by the other frame for triggering thetransmission of the above-mentioned frame by the terminal device 200.The communication control unit 243 controls the transmission of theframe by the terminal device 200 so that the above-mentioned frame istransmitted using the above-mentioned shared band according to thereception of the above-mentioned other frame.

For example, the above-mentioned other frame has a reception addressfield (or another field) and includes a predetermined value in thereception address field (or the other field). Thus, the communicationcontrol unit 243 controls the transmission of the frame by the terminaldevice 200 so that the above-mentioned frame is transmitted using theabove-mentioned shared band according to the reception of another frameincluding the above-mentioned predetermine value in the receptionaddress field (or the other field).

As an example, the above-mentioned other frame is an RTS frame andtriggers the transmission of a CTS frame by the above-mentioned terminaldevice 200. That is, the base station 100 transmits the RTS frame usingthe above-mentioned shared band and the terminal device 200 transmitsCTS using the above-mentioned shared band according to the reception ofthe RTS frame.

As mentioned above, the above-mentioned frame is transmitted by theterminal device 200. Thereby, for example, the wireless LAN device whichreceives the above-mentioned frame transmitted by the terminal device200 can set the above-mentioned NAV. That is, it is possible to causethe wireless LAN device positioned in the periphery of the terminaldevice 200 which is the above-mentioned device candidate to set the NAV.Consequently, when the cellular communication is performed using theabove-mentioned shared band, the use of the above-mentioned shared bandby the wireless LAN device positioned in the periphery of theabove-mentioned terminal device 200 can be prevented. That is, a hiddenterminal problem can be solved.

(c) Cellular Communication

For example, the communication control unit 243 controls the cellularcommunication by the terminal device 200.

For example, the communication control unit 243 controls the cellularcommunication by the terminal device 200 using the above-mentionedshared band. Also, for example, the communication control unit 243controls the cellular communication by the terminal device 200 using thecellular band.

<<4. Flow of Process>>

Next, examples of the process according to the embodiment of the presentdisclosure will be described with reference to FIGS. 15 to 17.

(First Example)

FIG. 15 is a sequence diagram illustrating the first example of aschematic flow of the process according to the embodiment of the presentdisclosure.

The base station 100 acquires device candidate information indicatingthe terminal device 200 which is the device candidate for performingcellular communication using a shared band and notifies the terminaldevice 200 that the terminal device 200 is the above-mentioned devicecandidate using a cellular band (S301).

Thereafter, the terminal device 200 performs carrier sensing for theabove-mentioned shared band (S303). The terminal device 200 reports aresult of the above-mentioned carrier sensing to the base station 100using the cellular band (S305).

Further, the base station 100 determines whether to use theabove-mentioned shared band in the cellular communication on the basisof the result of the above-mentioned carrier sensing (S307). Forexample, the base station 100 determines to use the above-mentionedshared band in the cellular communication.

The base station 100 performs the carrier sensing for theabove-mentioned shared band (S309) and transmits an RTS frame when aperiod in which no signal is transmitted using the above-mentionedshared band becomes a sum of a DIFS and a backoff time (S311).

Also, the base station 100 transmits a frame transmission instructionmessage including timing information and duration information using thecellular band (S313).

Then, the terminal device 200 transmits a CTS frame including theabove-mentioned duration information using the above-mentioned sharedband at a timing specified from the above-mentioned timing information(S315).

The base station 100 and the terminal device 200 perform the cellularcommunication using the above-mentioned shared band in a period afterthe transmission of the CTS frame (S317). That is, the base station 100and the terminal device 200 transmit signals of the cellularcommunication in the period.

Also, no frame transmission instruction message is transmitted and theterminal device 200 may transmit the CTS frame using the above-mentionedshared band according to the reception of the RTS frame transmittedusing the above-mentioned shared band by the base station 100.

Also, as described above, the base station 100 may transmit another typeof frame in place of the RTS frame. Also, the terminal device 200 maytransmit another type of frame in place of the CTS frame.

(Second Example)

FIG. 16 is a sequence diagram illustrating the second example of aschematic flow of the process according to the embodiment of the presentdisclosure. The second example is an example in which a result ofcarrier sensing is not reported by the terminal device 200.

Steps S331 to S341 of the above-mentioned second example illustrated inFIG. 16 are the same as steps S301 and S309 to S317 of theabove-mentioned first example illustrated in FIG. 15. Consequently,redundant description will be omitted here.

(Third Example)

FIG. 17 is a sequence diagram illustrating the third example of aschematic flow of the process according to the embodiment of the presentdisclosure. The third example is an example in which no frame (forexample, a CTS frame) is transmitted by the terminal device 200.

Steps S361 to S371 of the above-mentioned third example illustrated inFIG. 17 are the same as steps S301 to S311 of the above-mentioned firstexample illustrated in FIG. 15. Consequently, redundant description willbe omitted here and only step S373 will be described.

The base station 100 and the terminal device 200 perform theabove-mentioned cellular communication using the above-mentioned sharedband in a period after the transmission of the RTS frame (S373). Thatis, the base station 100 and the terminal device 200 transmit a signalof the cellular communication in the period.

<<5. First Modified Example>>

Next, the first modified example of the embodiment of the presentdisclosure will be described with reference to FIGS. 18 and 19.

(Summary)

In the first modified example, the base station 100 synchronizeswireless communication using a shared band with wireless communicationusing a cellular band. Also, the terminal device 200 achieves thesynchronization (achieve) for the above-mentioned shared band on thebasis of a result of achieving the synchronization for the cellularband.

Thereby, for example, when the above-mentioned shared band is used inthe cellular communication, the terminal device 200 can more quicklystart the cellular communication using the above-mentioned shared band.

(Base Station 100: Communication Control Unit 153)

(e) Cellular Communication

In the first modified example, the communication control unit 153synchronizes the wireless communication using the cellular band with thewireless communication using the above-mentioned shared band.

For example, the communication control unit 153 synchronizes thewireless communication using the cellular band with the wirelesscommunication using the above-mentioned shared band in a time direction.More specifically, for example, the communication control unit 153synchronizes a radio frame for the cellular band with a radio frame forthe above-mentioned shared band.

Also, for example, the same transceiver is used for the above cellularband and the above-mentioned shared band, and the wireless communicationof the above-mentioned cellular band and the above-mentioned shared bandare synchronized in a frequency direction. Here, the synchronization inthe frequency direction means that a deviation in the frequencydirection is a predetermined degree (for example, such as 500 Hz) orless.

(Terminal Device 200: Communication Control Unit 243)

(c) Cellular Communication

In the first modified example, the communication control unit 243achieves the synchronization for the above-mentioned shared band on thebasis of a result of achieving the synchronization for the cellularband.

For example, the communication control unit 243 achieves thesynchronization for the above-mentioned cellular band. When theabove-mentioned shared band is configured to be used in the cellularcommunication, the communication control unit 243 achieves thesynchronization for the above-mentioned shared band on the basis of aresult of achieving synchronization for the above-mentioned cellularband. Hereinafter, a specific example will be described with referenceto FIG. 18.

FIG. 18 is an explanatory diagram illustrating the achievement ofsynchronization for the shared band. Referring to FIG. 18, the cellularband and the shared band are illustrated. The base station 100synchronizes the wireless communication using the cellular band with thewireless communication using the shared band in the time direction andthe frequency direction. First, the communication control unit 243achieves synchronization in the time direction and the frequencydirection for the cellular band before the shared band is used in thecellular communication. Thereafter, when the use of the shared band forthe cellular communication starts, the communication control unit 243achieves the synchronization in the time direction and the frequencydirection for the above-mentioned shared band on the basis of thesynchronization result in the time direction and the frequency directionfor the above-mentioned cellular band. For example, the communicationcontrol unit 243 achieves the synchronization in the time direction forthe above-mentioned shared band by matching the radio frame for theabove-mentioned shared band to the radio frame for the above-mentionedcellular band. Also, for example, the communication control unit 243achieves the synchronization of the frequency direction for theabove-mentioned shared band by correcting deviation in the frequencydirection for the above-mentioned shared band as in the correction ofthe deviation in the frequency direction for the above-mentionedcellular band.

For example, when the above-mentioned shared band is used in thecellular communication according to the achievement of thesynchronization for the above-mentioned shared band as described above,the terminal device 200 can more quickly start the cellularcommunication using the above-mentioned shared band.

More specifically, when the terminal device 200 achieves thesynchronization for the above-mentioned shared band, for example, afterthe above-mentioned shared band starts to be used in the cellularcommunication, starting the cellular communication (for example, thetransmission/reception of data) using the above-mentioned shared band bythe terminal device 200 can be delayed. Also, because no synchronizationsignal for the above-mentioned shared band is transmitted before theabove-mentioned shared band is used in the cellular communication, theterminal device 200 cannot acquire the synchronization for theabove-mentioned shared band. Therefore, as described above, for example,by achieving the synchronization for the shared band on the basis of aresult of achieving the synchronization for the cellular band, theterminal device 200 can more quickly start the cellular communicationusing the above-mentioned shared band.

(Flow of Process)

FIG. 19 is a flowchart illustrating an example of a schematic flow ofthe process according to the first modified example of the presentembodiment. This process is a process of the terminal device 200.

The communication control unit 243 achieves synchronization for acellular band (S401).

The communication control unit 243 determines whether the terminaldevice 200 uses a shared band (S403). When the terminal device 200 doesnot use the shared band (S403: NO), the process returns to step S401.

When the terminal device 200 uses the shared band (S403: YES), thecommunication control unit 243 achieves synchronization for theabove-mentioned shared band on the basis of a result of achieving thesynchronization for the cellular band (S405). The process ends.

<<6. Second Modified Example>>

Next, the first modified example of the embodiment of the presentdisclosure will be described with reference to FIG. 20.

(Summary)

In the first modified example, the base station 100 notifies one or moreterminal devices 200 of a period in which cellular communication isperformed using a shared band. The one or more terminal devices 200 arenot limited to the device candidate for performing the cellularcommunication using the above-mentioned shared band. Thereby, forexample, the terminal device 200 can perform measurement for theabove-mentioned shared band.

Also, the terminal device 200 recognizes the above-mentioned periodthrough a notification by the base station 100 and performs measurementfor the above-mentioned shared band in the period. Thereby, for example,the base station 100 can more appropriately determine the devicecandidate for performing the cellular communication using theabove-mentioned shared band.

(Base Station 100: Communication Control Unit 153)

(f) Notification of Period in Which Cellular Communication is PerformedUsing Shared Band

In the second modified example, the communication control unit 153notifies the one or more terminal devices 200 of the period in which thecellular communication is performed using the above-mentioned sharedband. The one or more terminal devices 200 are not limited to the devicecandidate for performing the cellular communication using theabove-mentioned shared band.

Period in Which Cellular Communication is Performed Using Shared Band

For example, the base station 100 transmits a frame (for example, an RTSframe) including duration information for setting an NAV using theabove-mentioned shared band after the carrier sensing for theabove-mentioned shared band. Then, the period in which the cellularcommunication is performed using the above-mentioned shared band isdetermined. The communication control unit 153 notifies the one or moreterminal devices 200 of the period.

Timing of Notification

For example, the communication control unit 153 notifies one or moreterminal devices 200 of the above-mentioned period after theabove-mentioned shared band is available in the cellular communication.

Specifically, for example, the communication control unit 153 notifiesthe one or more terminal devices 200 of the above-mentioned period aftera frame including duration information for setting the NAV istransmitted by the base station 100 and/or the terminal device 200.

Specific Content of Notification

As an example, the communication control unit 153 notifies the one ormore terminal devices 200 of the above-mentioned period through thenotification of an end time-point of the above-mentioned period. Asanother example, the communication control unit 153 may notify the oneor more terminal devices 200 of the above-mentioned period through anotification of a length of the above-mentioned period.

Technique of Notification

As an example, the communication control unit 153 notifies the one ormore terminal devices 200 of the above-mentioned period by individualsignaling (for example, RRC signaling) for each of the one or moreterminal devices 200. In this case, for example, the communicationcontrol unit 153 notifies the one or more terminal devices 200 of theabove-mentioned period by the above-mentioned individual signaling usingthe cellular band used in the cellular communication between the basestation 100 and each of the above-mentioned one or more terminal devices200.

As another example, the communication control unit 153 may notify theone or more terminal devices 200 of the above-mentioned period in anSIB. In this case, for example, the communication control unit 153 maynotify the one or more terminal devices 200 of the above-mentionedperiod in the SIB of each cellular band (for example, each CC). That is,each cellular band (for example, each CC) may be used in thenotification of the above-mentioned period.

As described above, the one or more terminal devices 200 are notified ofthe period in which the cellular communication is performed using theabove-mentioned shared band. Thereby, for example, the terminal device200 can perform measurement for the above-mentioned shared band. Morespecifically, because a CRS or the like is not transmitted using theabove-mentioned shared band, for example, while the above-mentionedshared band is not used in the cellular communication, the terminaldevice 200 cannot perform the measurement for the above-mentioned sharedband. Therefore, for example, the terminal device 200 can perform themeasurement for the above-mentioned shared band by notifying theterminal device 200 of the period in which the cellular communication isperformed using the above-mentioned shared band.

(g) Determination of Device Candidate

For example, in the second modified example, the communication controlunit 153 determines the above-mentioned device candidate (that is, adevice candidate for performing the cellular communication using theshared band) on the basis of a result of measurement for theabove-mentioned shared band by at least some of the above-mentioned oneor more terminal devices.

As described below, when the notification of the period in which thecellular communication is performed using the above-mentioned sharedband is provided, the terminal device 200 performs measurement for theabove-mentioned shared band in the period and notifies the base station100 of the result of the measurement for the above-mentioned sharedband. The communication control unit 153 determines the above-mentioneddevice candidate on the basis of the above-mentioned measurement result.As an example, a predetermined number of terminal devices 200 withbetter communication quality in the above-mentioned shared band aredetermined as the above-mentioned device candidate.

Thereby, for example, the communication quality of cellularcommunication using the above-mentioned shared band can be improved.

(Terminal Device 200: Recognition Unit 241)

In the second modified example, the recognition unit 241 recognizes theperiod in which the cellular communication is performed using theabove-mentioned shared band through the notification by the base station100.

As described above, the base station 100 notifies the terminal device200 of the period in which the cellular communication is performed usingthe above-mentioned shared band. Then, the recognition unit 241recognizes the period.

(Terminal Device 200: Communication Control Unit 243)

(d) Measurement

In the second modified example, the communication control unit 243performs measurement for the above-mentioned shared band in the periodin which the cellular communication is performed using theabove-mentioned shared band.

For example, the communication control unit 243 performs measurement forCRS to be transmitted in the above-mentioned shared band in theabove-mentioned period. For example, the communication control unit 243measures reference signal received power (RSRP) and/or reference signalreceived quality (RSRQ) for the above-mentioned shared band.

Also, the communication control unit 243 reports the result of themeasurement for the above-mentioned shared band to the base station 100.That is, the communication control unit 243 reports the measurement ofthe above-mentioned shared band. As an example, the communicationcontrol unit 243 reports the measurement of the above-mentioned sharedband regardless of the above-mentioned measurement result. As anotherexample, the communication control unit 243 may perform the measurementreport of the above-mentioned shared band when the above-mentionedmeasurement result satisfies a predetermined condition (for example, ameasurement value exceeds a predetermined threshold value).

Thereby, for example, the base station 100 can more appropriatelydetermine the above-mentioned device candidate.

(Flow of Process)

FIG. 20 is a sequence diagram illustrating an example of a schematicflow of the process according to the second modified example of thepresent embodiment.

The base station 100 notifies the one or more terminal devices 200 of aperiod in which a shared band is used in cellular communication (S421).

Then, each of the above-mentioned one or more terminal devices 200performs measurement for the above-mentioned shared band in theabove-mentioned period (S423) and reports a result of theabove-mentioned measurement to the base station 100 (S425).

Thereafter, the base station 100 determines a device candidate forperforming the cellular communication using the above-mentioned sharedband on the basis of the above-mentioned result of the above-mentionedmeasurement from the above-mentioned one or more terminal devices 200(S427).

Also, only some of the above-mentioned terminal devices 200 rather thanall of the above-mentioned one or more terminal devices 200 may reportthe above-mentioned measurement result.

<<7. Applications>>

Technology according to the present disclosure is applicable to variousproducts. For example, the base station 100 may be implemented as a typeof eNB such as a macro eNB or a small eNB. The small eNB may be an eNBto cover a cell smaller than a macro cell such as a pico eNB, a microeNB, or a home (femto) eNB. Conversely, the base station 100 may also berealized as another type of base station, such as a NodeB or a basetransceiver station (BTS). The base station 100 may also include a mainunit that controls wireless communication (also called a base stationdevice), and one or more remote radio heads (RRHs) placed in a locationseparate from the main unit. Also, various types of terminals to bedescribed below temporarily or semi-permanently execute a base stationfunction and therefore may operate as the base station 100.

In addition, the terminal device 200 may be realized as, for example, amobile terminal such as a smartphone, a tablet personal computer (PC), anotebook PC, a portable game console, a portable/dongle-style mobilerouter, or a digital camera, or as an in-vehicle terminal such as a carnavigation device. In addition, the terminal device 200 may also berealized as a terminal that conducts machine-to-machine (M2M)communication (also called a machine-type communication (MTC) terminal).Furthermore, at least a part of constituent elements of the terminaldevice 200 may be realized as a module mounted onboard these terminals(for example, an integrated circuit module configured on a single die).

<7.1. Application Examples Regarding Base Station>

(First Application Example)

FIG. 21 is a block diagram illustrating a first example of a schematicconfiguration of an eNB to which the technology of the presentdisclosure may be applied. An eNB 800 includes one or more antennas 810and a base station device 820. Each antenna 810 and the base stationdevice 820 may be connected to each other via an RF cable.

Each of the antennas 810 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the base station device 820 to transmit and receive radiosignals. The eNB 800 may include the multiple antennas 810, asillustrated in FIG. 21. For example, the multiple antennas 810 may becompatible with multiple frequency bands used by the eNB 800. AlthoughFIG. 21 illustrates the example in which the eNB 800 includes themultiple antennas 810, the eNB 800 may also include a single antenna810.

The base station device 820 includes a controller 821, a memory 822, anetwork interface 823, and a wireless communication interface 825.

The controller 821 may be, for example, a CPU or a DSP, and operatesvarious functions of a higher layer of the base station device 820. Forexample, the controller 821 generates a data packet from data in signalsprocessed by the wireless communication interface 825, and transfers thegenerated packet via the network interface 823. The controller 821 maybundle data from multiple base band processors to generate the bundledpacket, and transfer the generated bundled packet. The controller 821may have logical functions of performing control such as radio resourcecontrol, radio bearer control, mobility management, admission control,and scheduling. The control may be performed in corporation with an eNBor a core network node in the vicinity. The memory 822 includes RAM andROM, and stores a program that is executed by the controller 821, andvarious types of control data (such as a terminal list, transmissionpower data, and scheduling data).

The network interface 823 is a communication interface for connectingthe base station device 820 to a core network 824. The controller 821may communicate with a core network node or another eNB via the networkinterface 823. In that case, the eNB 800, and the core network node orthe other eNB may be connected to each other through a logical interface(such as an S1 interface and an X2 interface). The network interface 823may also be a wired communication interface or a wireless communicationinterface for radio backhaul. If the network interface 823 is a wirelesscommunication interface, the network interface 823 may use a higherfrequency band for wireless communication than a frequency band used bythe wireless communication interface 825.

The wireless communication interface 825 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and provides radioconnection to a terminal positioned in a cell of the eNB 800 via theantenna 810. The wireless communication interface 825 may typicallyinclude, for example, a baseband (BB) processor 826 and an RF circuit827. The BB processor 826 may perform, for example, encoding/decoding,modulating/demodulating, and multiplexing/demultiplexing, and performsvarious types of signal processing of layers (such as L1, medium accesscontrol (MAC), radio link control (RLC), and a packet data convergenceprotocol (PDCP)). The BB processor 826 may have a part or all of theabove-mentioned logical functions instead of the controller 821. The BBprocessor 826 may be a memory that stores a communication controlprogram, or a module that includes a processor and a related circuitconfigured to execute the program. Updating the program may allow thefunctions of the BB processor 826 to be changed. The module may be acard or a blade that is inserted into a slot of the base station device820. Alternatively, the module may also be a chip that is mounted on thecard or the blade. Meanwhile, the RF circuit 827 may include, forexample, a mixer, a filter, and an amplifier, and transmits and receivesradio signals via the antenna 810.

The wireless communication interface 825 may include the multiple BBprocessors 826, as illustrated in FIG. 21. For example, the multiple BBprocessors 826 may be compatible with multiple frequency bands used bythe eNB 800. The wireless communication interface 825 may include themultiple RF circuits 827, as illustrated in FIG. 21. For example, themultiple RF circuits 827 may be compatible with multiple antennaelements. Although FIG. 21 illustrates the example in which the wirelesscommunication interface 825 includes the multiple BB processors 826 andthe multiple RF circuits 827, the wireless communication interface 825may also include a single BB processor 826 or a single RF circuit 827.

Furthermore, in addition to a cellular communication scheme, thewireless communication interface 825 may support a radio LANcommunication scheme. In that case, the wireless communication interface825 may include the BB processor 826 and the RF circuit 827 in the radioLAN communication scheme.

In the eNB 800 illustrated in FIG. 21, the information acquisition unit151 and the communication control unit 153 described with reference toFIG. 6 may be implemented in the wireless communication interface 825(for example, the BB processor). Alternatively, a part of thesestructural elements may be implemented in the controller 821. As oneexample, the eNB 800 is equipped with a module including a part (forexample, the BB processor 826) or all of the wireless communicationinterface 825 and/or the controller 821, and the information acquisitionunit 151 and the communication control unit 153 may be implemented inthe module. In this case, the above-mentioned module may store a programfor causing the processor to function as the information acquisitionunit 151 and the communication control unit 153 (in other words, aprogram for causing the processor to execute the operation of theinformation acquisition unit 151 and the communication control unit 153)and execute the program. As another example, a program for causing theprocessor to function as the information acquisition unit 151 and thecommunication control unit 153 is installed in the eNB 800, and thewireless communication interface 825 (for example, the BB processor 826)and/or the controller 821 may execute the program. As mentioned above,the eNB 800, the base station device 820, or the above-mentioned modulemay be provided as the device including the information acquisition unit151 and the communication control unit 153, and the program for causingthe processor to function as the information acquisition unit 151 andthe communication control unit 153 may be provided. Also, a readablestorage medium storing the above-mentioned program may be provided.

Also, in the eNB 800 illustrated in FIG. 21, the wireless communicationunit 120 described with reference to FIG. 6 may be implemented in thewireless communication interface 825 (for example, the RF circuit 827).Also, the antenna unit 110 may be implemented in the antenna 810. Also,the network communication unit 130 may be implemented in the controller821 and/or the network interface 823.

(Second Application Example)

FIG. 22 is a block diagram illustrating a second example of a schematicconfiguration of an eNB to which the technology of the presentdisclosure may be applied. An eNB 830 includes one or more antennas 840,a base station device 850, and an RRH 860. Each antenna 840 and the RRH860 may be connected to each other via an RF cable. The base stationdevice 850 and the RRH 860 may be connected to each other via a highspeed line such as an optical fiber cable.

Each of the antennas 840 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the RRH 860 to transmit and receive radio signals. The eNB 830may include the multiple antennas 840, as illustrated in FIG. 22. Forexample, the multiple antennas 840 may be compatible with multiplefrequency bands used by the eNB 830. Although FIG. 22 illustrates theexample in which the eNB 830 includes the multiple antennas 840, the eNB830 may also include a single antenna 840.

The base station device 850 includes a controller 851, a memory 852, anetwork interface 853, a wireless communication interface 855, and aconnection interface 857. The controller 851, the memory 852, and thenetwork interface 853 are the same as the controller 821, the memory822, and the network interface 823 described with reference to FIG. 21.

The wireless communication interface 855 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and provides wirelesscommunication to a terminal positioned in a sector corresponding to theRRH 860 via the RRH 860 and the antenna 840. The wireless communicationinterface 855 may typically include, for example, a BB processor 856.The BB processor 856 is the same as the BB processor 826 described withreference to FIG. 21, except the BB processor 856 is connected to the RFcircuit 864 of the RRH 860 via the connection interface 857. Thewireless communication interface 855 may include the multiple BBprocessors 856, as illustrated in FIG. 22. For example, the multiple BBprocessors 856 may be compatible with multiple frequency bands used bythe eNB 830. Although FIG. 22 illustrates the example in which thewireless communication interface 855 includes the multiple BB processors856, the wireless communication interface 855 may also include a singleBB processor 856.

Furthermore, in addition to a cellular communication scheme, thewireless communication interface 855 may support a radio LANcommunication scheme. In that case, the wireless communication interface825 may include the BB processor 856 in the radio LAN communicationscheme.

The connection interface 857 is an interface for connecting the basestation device 850 (wireless communication interface 855) to the RRH860. The connection interface 857 may also be a communication module forcommunication in the above-mentioned high speed line that connects thebase station device 850 (wireless communication interface 855) to theRRH 860.

The RRH 860 includes a connection interface 861 and a wirelesscommunication interface 863.

The connection interface 861 is an interface for connecting the RRH 860(wireless communication interface 863) to the base station device 850.The connection interface 861 may also be a communication module forcommunication in the above-mentioned high speed line.

The wireless communication interface 863 transmits and receives radiosignals via the antenna 840. The wireless communication interface 863may typically include, for example, the RF circuit 864. The RF circuit864 may include, for example, a mixer, a filter, and an amplifier, andtransmits and receives radio signals via the antenna 840. The wirelesscommunication interface 863 may include multiple RF circuits 864, asillustrated in FIG. 22. For example, the multiple RF circuits 864 maysupport multiple antenna elements. Although FIG. 22 illustrates theexample in which the wireless communication interface 863 includes themultiple RF circuits 864, the wireless communication interface 863 mayalso include a single RF circuit 864.

In the eNB 830 illustrated in FIG. 22, the information acquisition unit151 and the communication control unit 153 described with reference toFIG. 6 may be implemented in the wireless communication interface 855(for example, the BB processor). Alternatively, at least a part of theinformation acquisition unit 151 and the communication control unit 153may be implemented in the controller 851. As one example, the eNB 830 isequipped with a module including a part (for example, the BB processor856) or all of the wireless communication interface 855 and/or thecontroller 851, and the information acquisition unit 151 and thecommunication control unit 153 may be implemented in the module. In thiscase, the above-mentioned module may store a program for causing theprocessor to function as the information acquisition unit 151 and thecommunication control unit 153 (in other words, a program for causingthe processor to execute the operation of the information acquisitionunit 151 and the communication control unit 153) and execute theprogram. As another example, a program for causing the processor tofunction as the information acquisition unit 151 and the communicationcontrol unit 153 is installed in the eNB 830, and the wirelesscommunication interface 855 (for example, the BB processor 856) and/orthe controller 851 may execute the program. As mentioned above, the eNB830, the base station device 850, or the above-mentioned module may beprovided as the device including the information acquisition unit 151and the communication control unit 153, and the program for causing theprocessor to function as the information acquisition unit 151 and thecommunication control unit 153 may be provided. Also, a readable storagemedium storing the above-mentioned program may be provided.

Also, in the eNB 830 illustrated in FIG. 22, the wireless communicationunit 120 described, for example, with reference to FIG. 6 may beimplemented in the wireless communication interface 863 (for example,the RF circuit 864). Also, the antenna unit 110 may be implemented inthe antenna 840. Also, the network communication unit 130 may beimplemented in the controller 851 and/or the network interface 853.

<7.2. Application Examples Regarding Terminal Device>

(First Application Example)

FIG. 23 is a block diagram illustrating an example of a schematicconfiguration of a smartphone 900 to which the technology of the presentdisclosure may be applied. The smartphone 900 includes a processor 901,a memory 902, a storage 903, an external connection interface 904, acamera 906, a sensor 907, a microphone 908, an input device 909, adisplay device 910, a speaker 911, a wireless communication interface912, one or more antenna switches 915, one or more antennas 916, a bus917, a battery 918, and an auxiliary controller 919.

The processor 901 may be, for example, a CPU or a system on a chip(SoC), and controls functions of an application layer and another layerof the smartphone 900. The memory 902 includes RAM and ROM, and stores aprogram that is executed by the processor 901, and data. The storage 903may include a storage medium such as a semiconductor memory and a harddisk. The external connection interface 904 is an interface forconnecting an external device such as a memory card and a universalserial bus (USB) device to the smartphone 900.

The camera 906 includes an image sensor such as a charge coupled device(CCD) and a complementary metal oxide semiconductor (CMOS), andgenerates a captured image. The sensor 907 may include a group ofsensors such as a measurement sensor, a gyro sensor, a geomagneticsensor, and an acceleration sensor. The microphone 908 converts soundsthat are input to the smartphone 900 to audio signals. The input device909 includes, for example, a touch sensor configured to detect touchonto a screen of the display device 910, a keypad, a keyboard, a button,or a switch, and receives an operation or an information input from auser. The display device 910 includes a screen such as a liquid crystaldisplay (LCD) and an organic light-emitting diode (OLED) display, anddisplays an output image of the smartphone 900. The speaker 911 convertsaudio signals that are output from the smartphone 900 to sounds.

The wireless communication interface 912 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and performs wirelesscommunication. The wireless communication interface 912 may typicallyinclude, for example, a BB processor 913 and an RF circuit 914. The BBprocessor 913 may perform, for example, encoding/decoding,modulating/demodulating, and multiplexing/demultiplexing, and performsvarious types of signal processing for wireless communication.Meanwhile, the RF circuit 914 may include, for example, a mixer, afilter, and an amplifier, and transmits and receives radio signals viathe antenna 916. The wireless communication interface 912 may also be aone chip module that has the BB processor 913 and the RF circuit 914integrated thereon. The wireless communication interface 912 may includethe multiple BB processors 934 and the multiple RF circuits 914, asillustrated in FIG. 23. Although FIG. 23 illustrates the example inwhich the wireless communication interface 912 includes the multiple BBprocessors 913 and the multiple RF circuits 914, the wirelesscommunication interface 912 may also include a single BB processor 913or a single RF circuit 914.

Furthermore, in addition to a cellular communication scheme, thewireless communication interface 912 may support a radio LANcommunication scheme. In that case, the wireless communication interface912 may include the BB processor 913 and the RF circuit 914 in the radioLAN communication scheme. Furthermore, in addition to a cellularcommunication scheme, the wireless communication interface 912 maysupport another type of wireless communication scheme such as ashort-distance wireless communication scheme and a near fieldcommunication scheme. In that case, the wireless communication interface912 may include the BB processor 913 and the RF circuit 914 for eachwireless communication scheme.

Each of the antenna switches 915 switches connection destinations of theantennas 916 among multiple circuits (such as circuits for differentwireless communication schemes) included in the wireless communicationinterface 912.

Each of the antennas 916 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the wireless communication interface 912 to transmit andreceive radio signals. The smartphone 900 may include the multipleantennas 916, as illustrated in FIG. 23. Although FIG. 23 illustratesthe example in which the smartphone 900 includes the multiple antennas916, the smartphone 900 may also include a single antenna 916.

Furthermore, the smartphone 900 may include the antenna 916 for eachwireless communication scheme. In that case, the antenna switches 915may be omitted from the configuration of the smartphone 900.

The bus 917 connects the processor 901, the memory 902, the storage 903,the external connection interface 904, the camera 906, the sensor 907,the microphone 908, the input device 909, the display device 910, thespeaker 911, the wireless communication interface 912, and the auxiliarycontroller 919 to each other. The battery 918 supplies power to blocksof the smartphone 900 illustrated in FIG. 33 via feeder lines, which arepartially shown as dashed lines in the figure. The auxiliary controller919 operates a minimum necessary function of the smartphone 900, forexample, in a sleep mode.

In the smartphone 900 illustrated in FIG. 23, the recognition unit 241and the communication control unit 243 described with reference to FIG.14 may be implemented in the wireless communication interface 912 (forexample, the BB processor 913). Alternatively, at least a part of thesestructural elements may be implemented in the processor 901 or theauxiliary controller 919. As one example, the smartphone 900 is equippedwith a module including a part (for example, the BB processor 913) orall of the wireless communication interface 912, the processor 901and/or the auxiliary controller 919, and the recognition unit 241 andthe communication control unit 243 may be implemented in the module. Inthis case, the above-mentioned module may store a program for causingthe processor to function as the recognition unit 241 and thecommunication control unit 243 (in other words, a program for causingthe processor to execute the operation of the recognition unit 241 andthe communication control unit 243) and execute the program. As anotherexample, a program for causing the processor to function as therecognition unit 241 and the communication control unit 243 is installedin the smartphone 900, and the wireless communication interface 912 (forexample, the BB processor 913), the processor 901, and/or the auxiliarycontroller 919 may execute the program. As mentioned above, thesmartphone 900, the base station device 820, or the above-mentionedmodule may be provided as the device including the recognition unit 241and the communication control unit 243, and the program for causing theprocessor to function as the recognition unit 241 and the communicationcontrol unit 243 may be provided. Also, a readable storage mediumstoring the above-mentioned program may be provided.

Also, in the smartphone 900 illustrated in FIG. 23, the wirelesscommunication unit 220 described, for example, with reference to FIG. 14may be implemented in the wireless communication interface 912 (forexample, the RF circuit 914). Also, the antenna unit 210 may beimplemented in the antenna 916.

(Second Application Example)

FIG. 24 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device 920 to which the technology ofthe present disclosure may be applied. The car navigation device 920includes a processor 921, a memory 922, a global positioning system(GPS) module 924, a sensor 925, a data interface 926, a content player927, a storage medium interface 928, an input device 929, a displaydevice 930, a speaker 931, a wireless communication interface 933, oneor more antenna switches 936, one or more antennas 937, and a battery938.

The processor 921 may be, for example, a CPU or a SoC, and controls anavigation function and another function of the car navigation device920. The memory 922 includes RAM and ROM, and stores a program that isexecuted by the processor 921, and data.

The GPS module 924 uses GPS signals received from a GPS satellite tomeasure a position (such as latitude, longitude, and altitude) of thecar navigation device 920. The sensor 925 may include a group of sensorssuch as a gyro sensor, a geomagnetic sensor, and an air pressure sensor.The data interface 926 is connected to, for example, an in-vehiclenetwork 941 via a terminal that is not shown, and acquires datagenerated by the vehicle, such as vehicle speed data.

The content player 927 reproduces content stored in a storage medium(such as a CD and a DVD) that is inserted into the storage mediuminterface 928. The input device 929 includes, for example, a touchsensor configured to detect touch onto a screen of the display device930, a button, or a switch, and receives an operation or an informationinput from a user. The display device 930 includes a screen such as aLCD or an OLED display, and displays an image of the navigation functionor content that is reproduced. The speaker 931 outputs sounds of thenavigation function or the content that is reproduced.

The wireless communication interface 933 supports any cellularcommunication scheme such as LET and LTE-Advanced, and performs wirelesscommunication. The wireless communication interface 933 may typicallyinclude, for example, a BB processor 934 and an RF circuit 935. The BBprocessor 934 may perform, for example, encoding/decoding,modulating/demodulating, and multiplexing/demultiplexing, and performsvarious types of signal processing for wireless communication.Meanwhile, the RF circuit 935 may include, for example, a mixer, afilter, and an amplifier, and transmits and receives radio signals viathe antenna 937. The wireless communication interface 933 may be a onechip module having the BB processor 934 and the RF circuit 935integrated thereon. The wireless communication interface 933 may includethe multiple BB processors 934 and the multiple RF circuits 935, asillustrated in FIG. 24. Although FIG. 24 illustrates the example inwhich the wireless communication interface 933 includes the multiple BBprocessors 934 and the multiple RF circuits 935, the wirelesscommunication interface 933 may also include a single BB processor 934or a single RF circuit 935.

Furthermore, in addition to a cellular communication scheme, thewireless communication interface 933 may support a radio LANcommunication scheme. In that case, the wireless communication interface933 may include the BB processor 934 and the RF circuit 935 in the radioLAN communication scheme. Furthermore, in addition to a cellularcommunication scheme, the wireless communication interface 933 maysupport another type of wireless communication scheme such as ashort-distance wireless communication scheme and a near fieldcommunication scheme. In that case, the wireless communication interface933 may include the BB processor 934 and the RF circuit 935 for eachwireless communication scheme.

Each of the antenna switches 936 switches connection destinations of theantennas 937 among multiple circuits (such as circuits for differentwireless communication schemes) included in the wireless communicationinterface 933.

Each of the antennas 937 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the wireless communication interface 933 to transmit andreceive radio signals. The car navigation device 920 may include themultiple antennas 937, as illustrated in FIG. 24. Although FIG. 24illustrates the example in which the car navigation device 920 includesthe multiple antennas 937, the car navigation device 920 may alsoinclude a single antenna 937.

Furthermore, the car navigation device 920 may include the antenna 937for each wireless communication scheme. In that case, the antennaswitches 936 may be omitted from the configuration of the car navigationdevice 920.

The battery 938 supplies power to blocks of the car navigation device920 illustrated in FIG. 24 via feeder lines that are partially shown asdashed lines in the figure. The battery 938 accumulates power suppliedform the vehicle.

In the car navigation device 920 illustrated in FIG. 24, the recognitionunit 241 and the communication control unit 243 described with referenceto FIG. 14 may be implemented in the wireless communication interface933 (for example, the BB processor 934). Alternatively, at least a partof these structural elements may be implemented in the processor 921. Asone example, the car navigation device 920 is equipped with a moduleincluding a part (for example, the BB processor 934) or all of thewireless communication interface 933, and/or processor 921, and therecognition unit 241 and the communication control unit 243 may beimplemented in the module. In this case, the above-mentioned module maystore a program for causing the processor to function as the recognitionunit 241 and the communication control unit 243 (in other words, aprogram for causing the processor to execute the operation of therecognition unit 241 and the communication control unit 243) and executethe program. As another example, a program for causing the processor tofunction as the recognition unit 241 and the communication control unit243 is installed in the car navigation device 920, and the wirelesscommunication interface 933 (for example, the BB processor 934), and/orthe processor 921 may execute the program. As mentioned above, the carnavigation device 920, the base station device 820, or theabove-mentioned module may be provided as the device including therecognition unit 241 and the communication control unit 243, and theprogram for causing the processor to function as the recognition unit241 and the communication control unit 243 may be provided. Also, areadable storage medium storing the above-mentioned program may beprovided.

Also, in the car navigation device 920 illustrated in FIG. 24, thewireless communication unit 220 described, for example, with referenceto FIG. 14 may be implemented in the wireless communication interface933 (for example, the RF circuit 935). Also, the antenna unit 210 may beimplemented in the antenna 937.

The technology of the present disclosure may also be realized as anin-vehicle system (or a vehicle) 940 including one or more blocks of thecar navigation device 920, the in-vehicle network 941, and a vehiclemodule 942. That is, the in-vehicle system (or the vehicle) 940 may beprovided as a device including the recognition unit 241 and thecommunication control unit 243. The vehicle module 942 generates vehicledata such as vehicle speed, engine speed, and trouble information, andoutputs the generated data to the in-vehicle network 941.

<<8. Conclusion>>

The devices and the processes according to the embodiments of thepresent disclosure have been described with reference to FIGS. 1 to 24.

According to the embodiment of the present disclosure, the base station100 includes an acquisition unit configured to acquire informationindicating a terminal device which is a device candidate for performingcellular communication using a frequency band shared between thecellular communication and wireless LAN communication (that is, a sharedband); and a control unit configured to notify the terminal device thatthe terminal device is the device candidate.

According to the embodiment of the present disclosure, the terminaldevice 200 includes a recognition unit configured to recognize that aterminal device 200 is a device candidate for performing cellularcommunication using a frequency band shared between the cellularcommunication and wireless LAN communication (that is, a shared band)through a notification by the base station 100; and a control unitconfigured to perform control for using the frequency band in thecellular communication when the terminal device 200 is the devicecandidate.

Thereby, for example, it is possible to more appropriately use theabove-mentioned frequency band (that is, the shared band) in thecellular system 1. Specifically, for example, it is possible to causethe terminal device 200 which is the above-mentioned device candidate toperform an operation for using the above-mentioned shared band in thecellular communication. Also, because a terminal device 200 which is notthe above-mentioned device candidate does not perform a specialoperation, an increase in the number of operations of the terminaldevice 200 which is not the above-mentioned device candidate can besuppressed.

The preferred embodiment(s) of the present disclosure has/have beendescribed above with reference to the accompanying drawings, whilst thepresent disclosure is not limited to the above examples, of course. Aperson skilled in the art may find various alterations and modificationswithin the scope of the appended claims, and it should be understoodthat they will naturally come under the technical scope of the presentdisclosure.

Although an example in which the cellular system is a system conformingto LTE, LTE-Advanced, or a compliant communication scheme has beendescribed, the present disclosure is not limited to such an example. Forexample, the communication system may be a system conforming to anothercommunication standard.

Also, for example, an example in which other wireless communicationdifferent from wireless communication of the cellular system is wirelessLAN communication (that is, wireless communication conforming to thewireless LAN standard) has been described, but the present disclosure isnot limited to the relevant examples. For example, the above-mentionedother wireless communication may be wireless communication (wirelesscommunication conforming to another communication standard adoptingCSMA) other than the wireless LAN communication.

Also, the processing steps in each process in this specification are notstrictly limited to execution in a time series following the sequencedescribed in a flowchart or a sequence diagram. For example, theprocessing steps in each process may be executed in a sequence thatdiffers from a sequence described herein as a flowchart or a sequencediagram, and furthermore may be executed in parallel.

Also, it is possible to create a computer program for causing theprocessor (for example, a CPU, a DSP, etc.) provided in a device (forexample, the base station and/or the terminal device) of the presentdescription to function as the components (for example, thecommunication control unit) of the above-mentioned device (in otherwords, a computer program for causing the above-mentioned processor toexecute the operation of the components of the above-mentioned device).Also, a storage medium storing the computer program may be provided.Also, a device (for example, a completed product or a module (acomponent, a processing circuit, a chip, etc.) for a completed product)including a memory that stores the above-mentioned computer program andone or more processors capable of executing the above-mentioned computerprogram may be provided. Also, a method including the operation of thecomponents of the above-mentioned device (for example, the communicationcontrol unit) is included in the technology according to the presentdisclosure.

In addition, the advantageous effects described in this specificationare merely for the sake of explanation or illustration, and are notlimiting. In other words, instead of or in addition to the aboveadvantageous effects, technology according to the present disclosure mayexhibit other advantageous effects that are clear to persons skilled inthe art from the description of this specification.

Additionally, the present technology may also be configured as below.

(1)

A device including:

an acquisition unit configured to acquire information indicating aterminal device which is a device candidate for performing wirelesscommunication of a cellular system using a frequency band shared betweenthe wireless communication of the cellular system and wirelesscommunication conforming to a wireless local area network (LAN)standard; and

a control unit configured to notify the terminal device that theterminal device is the device candidate.

(2)

The device according to (1), wherein the control unit notifies theterminal device that the terminal device is the device candidate beforethe frequency band is used in the wireless communication of the cellularsystem.

(3)

The device according to (1) or (2), wherein the control unit notifiesthe terminal device that the terminal device is the device candidateusing another frequency band for the cellular system.

(4)

The device according to any one of (1) to (3), wherein the control unitnotifies the terminal device that the terminal device is the devicecandidate in a system information block (SIB) or by individual signalingfor the terminal device.

(5)

The device according to any one of (1) to (4), wherein the control unitinstructs the terminal device to transmit a frame including durationinformation for setting a network allocation vector (NAV) using thefrequency band before the frequency band is used in the wirelesscommunication of the cellular system.

(6)

The device according to (5), wherein the control unit uses anotherfrequency band for the cellular system to instruct the terminal deviceto transmit the frame using the frequency band.

(7)

The device according to (6), wherein the control unit provides theterminal device with information which specifies a timing at which theframe is transmitted.

(8)

The device according to (6) or (7), wherein the control unit providesthe terminal device with the duration information or information whichspecifies the duration information.

(9)

The device according to (5), wherein the control unit instructs theterminal device to transmit the frame using the frequency band byanother frame for triggering the transmission of the frame by theterminal device.

(10)

The device according to any one of (1) to (9), wherein the control unitdetermines whether to use the frequency band in the wirelesscommunication of the cellular system on the basis of a result of carriersensing for the frequency band by the terminal device.

(11)

The device according to any one of (1) to (10), wherein the control unitsynchronizes wireless communication using another frequency band for thecellular system with wireless communication using the frequency band.

(12)

The device according to any one of (1) to (11), wherein the control unitnotifies one or more terminal devices for performing wirelesscommunication of the cellular system of a period in which the wirelesscommunication of the cellular system is performed using the frequencyband.

(13)

The device according to (12), wherein the control unit determines thedevice candidate on the basis of a result of performing measurement forthe frequency band by at least some of the one or more terminal devices.

(14)

The device according to any one of (1) to (13), wherein the device is abase station of the cellular system, a base station device of the basestation, or a module of the base station device.

(15)

A device including:

a recognition unit configured to recognize that a terminal device is adevice candidate for performing wireless communication of a cellularsystem using a frequency band shared between the wireless communicationof the cellular system and wireless communication conforming to awireless local area network (LAN) standard through a notification by abase station of the cellular system; and

a control unit configured to perform control for using the frequencyband in the wireless communication of the cellular system when theterminal device is the device candidate.

(16)

The device according to (15), wherein the control includes controllingtransmission of a frame by the terminal device so that the frameincluding duration information for setting a NAV is transmitted usingthe frequency band.

(17)

The device according to (15) or (16), wherein the control includesnotifying the base station of a result of carrier sensing by theterminal device.

(18)

The device according to any one of (15) to (17), wherein the controlunit achieves synchronization for the frequency band on the basis of aresult of achieving synchronization for another frequency band for thecellular system.

(19)

The device according to any one of (15) to (18),

wherein the recognition unit recognizes a period in which the wirelesscommunication of the cellular system is performed using the frequencyband through a notification by the base station, and

wherein the control unit performs measurement for the frequency band inthe period.

(20)

The device according to any one of (15) to (19), wherein the device isthe terminal device or a module of the terminal device.

(21)

The device according to any one of (1) to (20),

wherein a duplex operation of the cellular system is frequency divisionduplex (FDD), and

wherein the frequency band is used as a downlink band in the cellularsystem.

(22)

A method including:

acquiring information indicating a terminal device which is a devicecandidate for performing wireless communication of a cellular systemusing a frequency band shared between the wireless communication of thecellular system and wireless communication conforming to a wirelesslocal area network (LAN) standard; and

notifying, by a processor, the terminal device that the terminal deviceis the device candidate.

(23)

A program for causing a processor to execute:

acquiring information indicating a terminal device which is a devicecandidate for performing wireless communication of a cellular systemusing a frequency band shared between the wireless communication of thecellular system and wireless communication conforming to a wirelesslocal area network (LAN) standard; and

notifying the terminal device that the terminal device is the devicecandidate.

(24)

A readable recording medium having a program recorded thereon, theprogram causing a processor to execute:

acquiring information indicating a terminal device which is a devicecandidate for performing wireless communication of a cellular systemusing a frequency band shared between the wireless communication of thecellular system and wireless communication conforming to a wirelesslocal area network (LAN) standard; and

notifying the terminal device that the terminal device is the devicecandidate.

(25)

A method including:

recognizing that a terminal device is a device candidate for performingwireless communication of a cellular system using a frequency bandshared between the wireless communication of the cellular system andwireless communication conforming to a wireless local area network (LAN)standard through a notification by a base station of the cellularsystem; and

performing, by a processor, control for using the frequency band in thewireless communication of the cellular system when the terminal deviceis the device candidate.

(26)

A program for causing a processor to execute:

recognizing that a terminal device is a device candidate for performingwireless communication of a cellular system using a frequency bandshared between the wireless communication of the cellular system andwireless communication conforming to a wireless local area network (LAN)standard through a notification by a base station of the cellularsystem; and

performing control for using the frequency band in the wirelesscommunication of the cellular system when the terminal device is thedevice candidate.

(27)

A readable recording medium having a program recorded thereon, theprogram causing a processor to execute:

recognizing that a terminal device is a device candidate for performingwireless communication of a cellular system using a frequency bandshared between the wireless communication of the cellular system andwireless communication conforming to a wireless local area network (LAN)standard through a notification by a base station of the cellularsystem; and

performing control for using the frequency band in the wirelesscommunication of the cellular system when the terminal device is thedevice candidate.

(28)

A device including: a control unit configured to notify one or moreterminal devices for performing wireless communication of a cellularsystem of a period in which the wireless communication of the cellularsystem is performed using a frequency band shared between the wirelesscommunication of the cellular system and wireless communicationconforming to a wireless local area network (LAN) standard.

(29)

A method including: notifying, by a processor, one or more terminaldevices for performing wireless communication of a cellular system of aperiod in which the wireless communication of the cellular system isperformed using a frequency band shared between the wirelesscommunication of the cellular system and wireless communicationconforming to a wireless local area network (LAN) standard.

(30)

A program for causing a processor to execute: notifying one or moreterminal devices for performing wireless communication of a cellularsystem of a period in which the wireless communication of the cellularsystem is performed using a frequency band shared between the wirelesscommunication of the cellular system and wireless communicationconforming to a wireless local area network (LAN) standard.

(31)

A readable recording medium having a program recorded thereon, theprogram causing a processor to execute: notifying one or more terminaldevices for performing wireless communication of a cellular system of aperiod in which the wireless communication of the cellular system isperformed using a frequency band shared between the wirelesscommunication of the cellular system and wireless communicationconforming to a wireless local area network (LAN) standard.

(32)

A device including: a recognition unit configured to recognize a periodin which wireless communication of a cellular system is performed usinga frequency band shared between the wireless communication of thecellular system and wireless communication conforming to a wirelesslocal area network (LAN) standard through a notification by a basestation of the cellular system; and a control unit configured to performmeasurement for the frequency band in the period.

(33)

A method including: recognizing a period in which wireless communicationof a cellular system is performed using a frequency band shared betweenthe wireless communication of the cellular system and wirelesscommunication conforming to a wireless local area network (LAN) standardthrough a notification by a base station of the cellular system; andperforming, by a processor, measurement for the frequency band in theperiod.

(34)

A program for causing a processor to execute: recognizing a period inwhich wireless communication of a cellular system is performed using afrequency band shared between the wireless communication of the cellularsystem and wireless communication conforming to a wireless local areanetwork (LAN) standard through a notification by a base station of thecellular system; and performing measurement for the frequency band inthe period.

(35)

A readable recording medium having a program recorded thereon, theprogram causing a processor to execute: recognizing a period in whichwireless communication of a cellular system is performed using afrequency band shared between the wireless communication of the cellularsystem and wireless communication conforming to a wireless local areanetwork (LAN) standard through a notification by a base station of thecellular system; and performing measurement for the frequency band inthe period.

REFERENCE SIGNS LIST

-   1 cellular system-   10 cell-   30 access point-   40 communication area-   50 terminal device-   100 base station-   151 information acquisition unit-   153 communication control unit-   200 terminal device-   241 recognition unit-   243 communication control unit

The invention claimed is:
 1. A device comprising: circuitry including atleast a processor and a memory, the circuitry configured to: acquireinformation indicating a terminal device which is a device candidate forperforming a wireless communication of a cellular system using afrequency band shared between the wireless communication of the cellularsystem and another wireless communication conforming to a wireless localarea network (LAN) standard; notify the terminal device that theterminal device is the device candidate, wherein the terminal deviceperforms a carrier sensing for the frequency band and report a result ofthe carrier sensing to the device; determine whether or not to use thefrequency band based on the result from the terminal device; and executea carrier sensing for the frequency band and transmit a request-to-send(RTS) frame to the terminal device when a period, in which no signal istransmitted using the frequency band, becomes inter-frame space and aback-off time.
 2. The device according to claim 1, wherein the circuitryis further configured to notify the terminal device that the terminaldevice is the device candidate before the frequency band is used in thewireless communication of the cellular system.
 3. The device accordingto claim 1, wherein the circuitry is further configured to notify theterminal device that the terminal device is the device candidate usinganother frequency band for the cellular system.
 4. The device accordingto claim 1, wherein the circuitry is further configured to notify theterminal device that the terminal device is the device candidate in asystem information block (SIB) or by an individual signaling for theterminal device.
 5. The device according to claim 1, wherein thecircuitry is further configured to instruct the terminal device totransmit a frame including duration information for setting a networkallocation vector (NAV) using the frequency band before the frequencyband is used in the wireless communication of the cellular system. 6.The device according to claim 5, wherein the circuitry is furtherconfigured to use another frequency band for the cellular system toinstruct the terminal device to transmit the frame using the frequencyband.
 7. The device according to claim 6, wherein the circuitry isfurther configured to provide the terminal device with information whichspecifies a timing at which the frame is transmitted.
 8. The deviceaccording to claim 6, wherein the circuitry is further configured toprovide the terminal device with the duration information or informationwhich specifies the duration information.
 9. The device according toclaim 5, wherein the circuitry is further configured to provide theterminal device to transmit the frame using the frequency band byanother frame for triggering the transmission of the frame by theterminal device.
 10. The device according to claim 1, wherein thecircuitry is further configured to determine whether to use thefrequency band in the wireless communication of the cellular systembased on a result of the carrier sensing for the frequency band by theterminal device.
 11. The device according to claim 1, wherein thecircuitry is further configured to synchronize another wirelesscommunication using another frequency band for the cellular system withthe wireless communication using the frequency band.
 12. The deviceaccording to claim 1, wherein the circuitry is further configured tonotify one or more terminal devices for performing the wirelesscommunication of the cellular system for a period in which the wirelesscommunication of the cellular system is performed using the frequencyband.
 13. The device according to claim 12, wherein the circuitry isfurther configured to determine the device candidate based on a resultof a measurement performed for the frequency band by at least some ofthe one or more terminal devices.
 14. The device according to claim 1,wherein the device is a base station of the cellular system, a basestation device of the base station, or a module of the base stationdevice.
 15. A device comprising: circuitry including at least aprocessor and a memory, the circuitry configured to: recognize that aterminal device is a device candidate for performing a wirelesscommunication of a cellular system using a frequency band shared betweenthe wireless communication of the cellular system and another wirelesscommunication conforming to a wireless local area network (LAN) standardthrough a notification by a base station of the cellular system; andcontrol for using the frequency band in the wireless communication ofthe cellular system when the terminal device is the device candidate,wherein the terminal device performs a carrier sensing for the frequencyband and report a result of the carrier sensing to the base station, thebase station determines whether or not to use the frequency band basedon the result from the terminal device and executes a carrier sensingfor the frequency band and transmit a request-to-send (RTS) frame to theterminal device when a period, in which no signal is transmitted usingthe frequency band, becomes inter-frame space and a back-off time. 16.The device according to claim 15, wherein the circuitry is furtherconfigured to include controlling transmission of a frame by theterminal device so that the frame including duration information forsetting a NAV is transmitted using the frequency band.
 17. The deviceaccording to claim 15, wherein the circuitry is further configured toinclude notifying the base station of a result of the carrier sensing bythe terminal device.
 18. The device according to claim 15, wherein thecircuitry is further configured to achieve synchronization for thefrequency band based on a result of achieving synchronization foranother frequency band for the cellular system.
 19. The device accordingto claim 15, wherein the circuitry recognizes a period in which thewireless communication of the cellular system is performed using thefrequency band through a notification by the base station, the circuitryis further configured to measure for the frequency band in the period.20. The device according to claim 15, wherein the device is the terminaldevice or a module of the terminal device.
 21. The device according toclaim 1, wherein a duplex operation of the cellular system is frequencydivision duplex (FDD), and wherein the frequency band is used as adownlink band in the cellular system.
 22. A terminal device comprising:circuitry including at least a processor and a memory, the circuitryconfigured to: receive information that the terminal device is a devicecandidate for performing a wireless communication of a cellular systemusing a frequency band shared between the wireless communication of thecellular system and another wireless communication conforming to awireless local area network (LAN) standard through a notification by abase station of the cellular system; receive duration information whichspecifies a period in which a wireless communication of the cellularsystem is performed using the frequency band through the notification bythe base station; perform a carrier sensing for the frequency band in atleast a part of the period; and report a result of the carrier sensingto the base station, wherein the frequency band is used for a secondarycomponent carrier, and another frequency band for a cellularcommunication is used as a primary component carrier, for the wirelesscommunication of the cellular system.
 23. The terminal device accordingto claim 22, wherein the circuitry is further configured to receive arequest-to-send (RTS) frame from the base station when a period, inwhich no signal is transmitted using the frequency band, becomesinter-frame space and a back-off time, wherein the other devicedetermines whether or not to use the frequency band based on the resultfrom the terminal device and performs a carrier sensing for thefrequency band before sending the RTS frame to the terminal device. 24.The terminal device according to claim 22, wherein the circuitry isfurther configured to measure for the frequency band in the period inwhich the wireless communication of the cellular system is performedusing the frequency band.
 25. The terminal device according to claim 24,wherein a reference signal received power (RSRP) of the frequency bandor a reference signal received quality (RSRQ) of the frequency band ismeasured.
 26. The terminal device according to claim 22, wherein thecircuitry is further configured to report the result of the carriersensing to the base station, the result indicating whether a signal istransmitted using the frequency band.